24ca92951f
To allow for flushing of batched geometry within Cogl we can't support users directly calling glReadPixels. glReadPixels is also awkward, not least because it returns upside down image data. All the unit tests have been swithed over and clutter_stage_read_pixels now sits on top of this too.
735 lines
18 KiB
C
735 lines
18 KiB
C
/*
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* Cogl
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*
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* An object oriented GL/GLES Abstraction/Utility Layer
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*
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* Copyright (C) 2007,2008,2009 Intel Corporation.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 02111-1307, USA.
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*/
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include "cogl.h"
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#include <string.h>
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#include <math.h>
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#include <stdlib.h>
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#ifdef HAVE_CLUTTER_GLX
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#include <dlfcn.h>
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#include <GL/glx.h>
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typedef CoglFuncPtr (*GLXGetProcAddressProc) (const guint8 *procName);
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#endif
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#include "cogl-debug.h"
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#include "cogl-internal.h"
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#include "cogl-util.h"
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#include "cogl-context.h"
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#include "cogl-material-private.h"
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#if defined (HAVE_COGL_GLES2) || defined (HAVE_COGL_GLES)
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#include "cogl-gles2-wrapper.h"
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#endif
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#ifdef COGL_GL_DEBUG
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/* GL error to string conversion */
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static const struct {
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GLuint error_code;
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const gchar *error_string;
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} gl_errors[] = {
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{ GL_NO_ERROR, "No error" },
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{ GL_INVALID_ENUM, "Invalid enumeration value" },
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{ GL_INVALID_VALUE, "Invalid value" },
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{ GL_INVALID_OPERATION, "Invalid operation" },
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{ GL_STACK_OVERFLOW, "Stack overflow" },
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{ GL_STACK_UNDERFLOW, "Stack underflow" },
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{ GL_OUT_OF_MEMORY, "Out of memory" },
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#ifdef GL_INVALID_FRAMEBUFFER_OPERATION_EXT
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{ GL_INVALID_FRAMEBUFFER_OPERATION_EXT, "Invalid framebuffer operation" }
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#endif
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};
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static const guint n_gl_errors = G_N_ELEMENTS (gl_errors);
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const gchar *
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cogl_gl_error_to_string (GLenum error_code)
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{
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gint i;
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for (i = 0; i < n_gl_errors; i++)
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{
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if (gl_errors[i].error_code == error_code)
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return gl_errors[i].error_string;
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}
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return "Unknown GL error";
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}
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#endif /* COGL_GL_DEBUG */
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void
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cogl_clear (const CoglColor *color, gulong buffers)
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{
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GLbitfield gl_buffers = 0;
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COGL_NOTE (DRAW, "Clear begin");
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cogl_clip_ensure ();
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if (buffers & COGL_BUFFER_BIT_COLOR)
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{
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GE( glClearColor (cogl_color_get_red_float (color),
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cogl_color_get_green_float (color),
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cogl_color_get_blue_float (color),
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0.0) );
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gl_buffers |= GL_COLOR_BUFFER_BIT;
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}
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if (buffers & COGL_BUFFER_BIT_DEPTH)
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gl_buffers |= GL_DEPTH_BUFFER_BIT;
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if (buffers & COGL_BUFFER_BIT_STENCIL)
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gl_buffers |= GL_STENCIL_BUFFER_BIT;
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if (!gl_buffers)
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{
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static gboolean shown = FALSE;
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if (!shown)
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{
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g_warning ("You should specify at least one auxiliary buffer "
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"when calling cogl_clear");
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}
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return;
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}
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glClear (gl_buffers);
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COGL_NOTE (DRAW, "Clear end");
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}
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static inline gboolean
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cogl_toggle_flag (CoglContext *ctx,
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gulong new_flags,
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gulong flag,
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GLenum gl_flag)
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{
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/* Toggles and caches a single enable flag on or off
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* by comparing to current state
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*/
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if (new_flags & flag)
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{
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if (!(ctx->enable_flags & flag))
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{
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GE( glEnable (gl_flag) );
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ctx->enable_flags |= flag;
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return TRUE;
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}
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}
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else if (ctx->enable_flags & flag)
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{
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GE( glDisable (gl_flag) );
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ctx->enable_flags &= ~flag;
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}
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return FALSE;
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}
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static inline gboolean
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cogl_toggle_client_flag (CoglContext *ctx,
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gulong new_flags,
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gulong flag,
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GLenum gl_flag)
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{
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/* Toggles and caches a single client-side enable flag
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* on or off by comparing to current state
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*/
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if (new_flags & flag)
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{
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if (!(ctx->enable_flags & flag))
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{
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GE( glEnableClientState (gl_flag) );
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ctx->enable_flags |= flag;
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return TRUE;
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}
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}
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else if (ctx->enable_flags & flag)
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{
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GE( glDisableClientState (gl_flag) );
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ctx->enable_flags &= ~flag;
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}
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return FALSE;
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}
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void
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cogl_enable (gulong flags)
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{
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/* This function essentially caches glEnable state() in the
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* hope of lessening number GL traffic.
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*/
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_COGL_GET_CONTEXT (ctx, NO_RETVAL);
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cogl_toggle_flag (ctx, flags,
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COGL_ENABLE_BLEND,
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GL_BLEND);
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cogl_toggle_flag (ctx, flags,
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COGL_ENABLE_BACKFACE_CULLING,
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GL_CULL_FACE);
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cogl_toggle_client_flag (ctx, flags,
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COGL_ENABLE_VERTEX_ARRAY,
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GL_VERTEX_ARRAY);
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cogl_toggle_client_flag (ctx, flags,
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COGL_ENABLE_COLOR_ARRAY,
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GL_COLOR_ARRAY);
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}
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gulong
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cogl_get_enable ()
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{
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_COGL_GET_CONTEXT (ctx, 0);
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return ctx->enable_flags;
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}
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void
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cogl_set_depth_test_enabled (gboolean setting)
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{
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if (setting)
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{
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glEnable (GL_DEPTH_TEST);
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glDepthFunc (GL_LEQUAL);
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}
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else
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glDisable (GL_DEPTH_TEST);
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}
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gboolean
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cogl_get_depth_test_enabled (void)
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{
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return glIsEnabled (GL_DEPTH_TEST) == GL_TRUE ? TRUE : FALSE;
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}
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void
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cogl_set_backface_culling_enabled (gboolean setting)
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{
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_COGL_GET_CONTEXT (ctx, NO_RETVAL);
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ctx->enable_backface_culling = setting;
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}
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gboolean
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cogl_get_backface_culling_enabled (void)
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{
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_COGL_GET_CONTEXT (ctx, FALSE);
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return ctx->enable_backface_culling;
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}
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void
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cogl_set_source_color (const CoglColor *color)
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{
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CoglColor premultiplied;
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_COGL_GET_CONTEXT (ctx, NO_RETVAL);
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/* In case cogl_set_source_texture was previously used... */
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cogl_material_remove_layer (ctx->default_material, 0);
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premultiplied = *color;
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cogl_color_premultiply (&premultiplied);
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cogl_material_set_color (ctx->default_material, &premultiplied);
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cogl_set_source (ctx->default_material);
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}
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static void
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project_vertex (const CoglMatrix *modelview_matrix,
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const CoglMatrix *projection_matrix,
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float *vertex)
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{
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int i;
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/* Apply the modelview matrix */
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cogl_matrix_transform_point (modelview_matrix,
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&vertex[0], &vertex[1],
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&vertex[2], &vertex[3]);
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/* Apply the projection matrix */
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cogl_matrix_transform_point (projection_matrix,
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&vertex[0], &vertex[1],
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&vertex[2], &vertex[3]);
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/* Convert from homogenized coordinates */
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for (i = 0; i < 4; i++)
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vertex[i] /= vertex[3];
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}
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static void
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set_clip_plane (GLint plane_num,
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const float *vertex_a,
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const float *vertex_b)
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{
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#if defined (HAVE_COGL_GLES2) || defined (HAVE_COGL_GLES)
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GLfloat plane[4];
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#else
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GLdouble plane[4];
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#endif
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GLfloat angle;
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CoglMatrix inverse_projection;
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_COGL_GET_CONTEXT (ctx, NO_RETVAL);
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/* Calculate the angle between the axes and the line crossing the
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two points */
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angle = atan2f (vertex_b[1] - vertex_a[1],
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vertex_b[0] - vertex_a[0]) * (180.0/G_PI);
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_cogl_current_matrix_push ();
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/* Load the identity matrix and multiply by the reverse of the
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projection matrix so we can specify the plane in screen
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coordinates */
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_cogl_current_matrix_identity ();
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cogl_matrix_init_from_array (&inverse_projection,
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ctx->inverse_projection);
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_cogl_current_matrix_multiply (&inverse_projection);
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/* Rotate about point a */
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_cogl_current_matrix_translate (vertex_a[0], vertex_a[1], vertex_a[2]);
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/* Rotate the plane by the calculated angle so that it will connect
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the two points */
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_cogl_current_matrix_rotate (angle, 0.0f, 0.0f, 1.0f);
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_cogl_current_matrix_translate (-vertex_a[0], -vertex_a[1], -vertex_a[2]);
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_cogl_current_matrix_state_flush ();
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plane[0] = 0;
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plane[1] = -1.0;
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plane[2] = 0;
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plane[3] = vertex_a[1];
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#if defined (HAVE_COGL_GLES2) || defined (HAVE_COGL_GLES)
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GE( glClipPlanef (plane_num, plane) );
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#else
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GE( glClipPlane (plane_num, plane) );
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#endif
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_cogl_current_matrix_pop ();
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}
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void
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_cogl_set_clip_planes (float x_offset,
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float y_offset,
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float width,
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float height)
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{
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CoglMatrix modelview_matrix;
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CoglMatrix projection_matrix;
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float vertex_tl[4] = { x_offset, y_offset, 0, 1.0 };
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float vertex_tr[4] = { x_offset + width, y_offset, 0, 1.0 };
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float vertex_bl[4] = { x_offset, y_offset + height, 0, 1.0 };
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float vertex_br[4] = { x_offset + width, y_offset + height,
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0, 1.0 };
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_cogl_get_matrix (COGL_MATRIX_PROJECTION,
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&projection_matrix);
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_cogl_get_matrix (COGL_MATRIX_MODELVIEW,
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&modelview_matrix);
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project_vertex (&modelview_matrix, &projection_matrix, vertex_tl);
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project_vertex (&modelview_matrix, &projection_matrix, vertex_tr);
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project_vertex (&modelview_matrix, &projection_matrix, vertex_bl);
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project_vertex (&modelview_matrix, &projection_matrix, vertex_br);
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/* If the order of the top and bottom lines is different from the
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order of the left and right lines then the clip rect must have
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been transformed so that the back is visible. We therefore need
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to swap one pair of vertices otherwise all of the planes will be
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the wrong way around */
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if ((vertex_tl[0] < vertex_tr[0] ? 1 : 0)
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!= (vertex_bl[1] < vertex_tl[1] ? 1 : 0))
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{
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float temp[4];
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memcpy (temp, vertex_tl, sizeof (temp));
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memcpy (vertex_tl, vertex_tr, sizeof (temp));
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memcpy (vertex_tr, temp, sizeof (temp));
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memcpy (temp, vertex_bl, sizeof (temp));
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memcpy (vertex_bl, vertex_br, sizeof (temp));
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memcpy (vertex_br, temp, sizeof (temp));
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}
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set_clip_plane (GL_CLIP_PLANE0, vertex_tl, vertex_tr);
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set_clip_plane (GL_CLIP_PLANE1, vertex_tr, vertex_br);
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set_clip_plane (GL_CLIP_PLANE2, vertex_br, vertex_bl);
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set_clip_plane (GL_CLIP_PLANE3, vertex_bl, vertex_tl);
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}
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void
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_cogl_add_stencil_clip (float x_offset,
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float y_offset,
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float width,
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float height,
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gboolean first)
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{
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_COGL_GET_CONTEXT (ctx, NO_RETVAL);
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_cogl_material_flush_gl_state (ctx->stencil_material, NULL);
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if (first)
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{
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GE( glEnable (GL_STENCIL_TEST) );
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/* Initially disallow everything */
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GE( glClearStencil (0) );
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GE( glClear (GL_STENCIL_BUFFER_BIT) );
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/* Punch out a hole to allow the rectangle */
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GE( glStencilFunc (GL_NEVER, 0x1, 0x1) );
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GE( glStencilOp (GL_REPLACE, GL_REPLACE, GL_REPLACE) );
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cogl_rectangle (x_offset, y_offset,
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x_offset + width, y_offset + height);
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}
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else
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{
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/* Add one to every pixel of the stencil buffer in the
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rectangle */
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GE( glStencilFunc (GL_NEVER, 0x1, 0x3) );
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GE( glStencilOp (GL_INCR, GL_INCR, GL_INCR) );
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cogl_rectangle (x_offset, y_offset,
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x_offset + width, y_offset + height);
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/* Subtract one from all pixels in the stencil buffer so that
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only pixels where both the original stencil buffer and the
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rectangle are set will be valid */
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GE( glStencilOp (GL_DECR, GL_DECR, GL_DECR) );
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_cogl_set_current_matrix (COGL_MATRIX_PROJECTION);
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_cogl_current_matrix_push ();
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_cogl_current_matrix_identity ();
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/* Cogl generally assumes the modelview matrix is current, so since
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* cogl_rectangle will be flushing GL state and emitting geometry
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* to OpenGL it will be confused if we leave the projection matrix
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* active... */
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_cogl_set_current_matrix (COGL_MATRIX_MODELVIEW);
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_cogl_current_matrix_push ();
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_cogl_current_matrix_identity ();
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cogl_rectangle (-1.0, -1.0, 1.0, 1.0);
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_cogl_current_matrix_pop ();
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_cogl_set_current_matrix (COGL_MATRIX_PROJECTION);
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_cogl_current_matrix_pop ();
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_cogl_set_current_matrix (COGL_MATRIX_MODELVIEW);
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}
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/* Restore the stencil mode */
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GE( glStencilFunc (GL_EQUAL, 0x1, 0x1) );
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GE( glStencilOp (GL_KEEP, GL_KEEP, GL_KEEP) );
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}
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void
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_cogl_disable_stencil_buffer (void)
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{
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GE( glDisable (GL_STENCIL_TEST) );
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}
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void
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_cogl_enable_clip_planes (void)
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{
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GE( glEnable (GL_CLIP_PLANE0) );
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GE( glEnable (GL_CLIP_PLANE1) );
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GE( glEnable (GL_CLIP_PLANE2) );
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GE( glEnable (GL_CLIP_PLANE3) );
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}
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void
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_cogl_disable_clip_planes (void)
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{
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GE( glDisable (GL_CLIP_PLANE3) );
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GE( glDisable (GL_CLIP_PLANE2) );
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GE( glDisable (GL_CLIP_PLANE1) );
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GE( glDisable (GL_CLIP_PLANE0) );
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}
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void
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cogl_viewport (guint width,
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guint height)
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{
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GE( glViewport (0, 0, width, height) );
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}
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void
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_cogl_setup_viewport (guint width,
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guint height,
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float fovy,
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float aspect,
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float z_near,
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float z_far)
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{
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float z_camera;
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CoglMatrix projection_matrix;
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GE( glViewport (0, 0, width, height) );
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/* For Ortho projection.
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* _cogl_current_matrix_ortho (0, width, 0, height, -1, 1);
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*/
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cogl_perspective (fovy, aspect, z_near, z_far);
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/*
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* In theory, we can compute the camera distance from screen as:
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*
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* 0.5 * tan (FOV)
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*
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* However, it's better to compute the z_camera from our projection
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* matrix so that we get a 1:1 mapping at the screen distance. Consider
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* the upper-left corner of the screen. It has object coordinates
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* (0,0,0), so by the transform below, ends up with eye coordinate
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*
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* x_eye = x_object / width - 0.5 = - 0.5
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* y_eye = (height - y_object) / width - 0.5 = 0.5
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* z_eye = z_object / width - z_camera = - z_camera
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*
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* From cogl_perspective(), we know that the projection matrix has
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* the form:
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*
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* (x, 0, 0, 0)
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* (0, y, 0, 0)
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* (0, 0, c, d)
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* (0, 0, -1, 0)
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*
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* Applied to the above, we get clip coordinates of
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*
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* x_clip = x * (- 0.5)
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* y_clip = y * 0.5
|
|
* w_clip = - 1 * (- z_camera) = z_camera
|
|
*
|
|
* Dividing through by w to get normalized device coordinates, we
|
|
* have, x_nd = x * 0.5 / z_camera, y_nd = - y * 0.5 / z_camera.
|
|
* The upper left corner of the screen has normalized device coordinates,
|
|
* (-1, 1), so to have the correct 1:1 mapping, we have to have:
|
|
*
|
|
* z_camera = 0.5 * x = 0.5 * y
|
|
*
|
|
* If x != y, then we have a non-uniform aspect ration, and a 1:1 mapping
|
|
* doesn't make sense.
|
|
*/
|
|
|
|
cogl_get_projection_matrix (&projection_matrix);
|
|
z_camera = 0.5 * projection_matrix.xx;
|
|
|
|
_cogl_current_matrix_identity ();
|
|
_cogl_current_matrix_translate (-0.5f, -0.5f, -z_camera);
|
|
_cogl_current_matrix_scale (1.0f / width, -1.0f / height, 1.0f / width);
|
|
_cogl_current_matrix_translate (0.0f, -1.0 * height, 0.0f);
|
|
}
|
|
|
|
CoglFeatureFlags
|
|
cogl_get_features (void)
|
|
{
|
|
_COGL_GET_CONTEXT (ctx, 0);
|
|
|
|
if (!ctx->features_cached)
|
|
_cogl_features_init ();
|
|
|
|
return ctx->feature_flags;
|
|
}
|
|
|
|
gboolean
|
|
cogl_features_available (CoglFeatureFlags features)
|
|
{
|
|
_COGL_GET_CONTEXT (ctx, 0);
|
|
|
|
if (!ctx->features_cached)
|
|
_cogl_features_init ();
|
|
|
|
return (ctx->feature_flags & features) == features;
|
|
}
|
|
|
|
void
|
|
cogl_get_viewport (float v[4])
|
|
{
|
|
/* FIXME: cogl_get_viewport should return a gint vec */
|
|
/* FIXME: cogl_get_viewport should only return a width + height
|
|
* (I don't think we need to support offset viewports) */
|
|
#if defined (HAVE_COGL_GLES2) || defined (HAVE_COGL_GLES)
|
|
GLint viewport[4];
|
|
int i;
|
|
|
|
glGetIntegerv (GL_VIEWPORT, viewport);
|
|
|
|
for (i = 0; i < 4; i++)
|
|
v[i] = (float)(viewport[i]);
|
|
#else
|
|
glGetFloatv (GL_VIEWPORT, v);
|
|
#endif
|
|
}
|
|
|
|
void
|
|
cogl_get_bitmasks (gint *red,
|
|
gint *green,
|
|
gint *blue,
|
|
gint *alpha)
|
|
{
|
|
GLint value;
|
|
|
|
if (red)
|
|
{
|
|
GE( glGetIntegerv(GL_RED_BITS, &value) );
|
|
*red = value;
|
|
}
|
|
|
|
if (green)
|
|
{
|
|
GE( glGetIntegerv(GL_GREEN_BITS, &value) );
|
|
*green = value;
|
|
}
|
|
|
|
if (blue)
|
|
{
|
|
GE( glGetIntegerv(GL_BLUE_BITS, &value) );
|
|
*blue = value;
|
|
}
|
|
|
|
if (alpha)
|
|
{
|
|
GE( glGetIntegerv(GL_ALPHA_BITS, &value ) );
|
|
*alpha = value;
|
|
}
|
|
}
|
|
|
|
void
|
|
cogl_set_fog (const CoglColor *fog_color,
|
|
CoglFogMode mode,
|
|
float density,
|
|
float z_near,
|
|
float z_far)
|
|
{
|
|
GLfloat fogColor[4];
|
|
GLenum gl_mode = GL_LINEAR;
|
|
|
|
fogColor[0] = cogl_color_get_red_float (fog_color);
|
|
fogColor[1] = cogl_color_get_green_float (fog_color);
|
|
fogColor[2] = cogl_color_get_blue_float (fog_color);
|
|
fogColor[3] = cogl_color_get_alpha_float (fog_color);
|
|
|
|
glEnable (GL_FOG);
|
|
|
|
glFogfv (GL_FOG_COLOR, fogColor);
|
|
|
|
#if HAVE_COGL_GLES
|
|
switch (mode)
|
|
{
|
|
case COGL_FOG_MODE_LINEAR:
|
|
gl_mode = GL_LINEAR;
|
|
break;
|
|
case COGL_FOG_MODE_EXPONENTIAL:
|
|
gl_mode = GL_EXP;
|
|
break;
|
|
case COGL_FOG_MODE_EXPONENTIAL_SQUARED:
|
|
gl_mode = GL_EXP2;
|
|
break;
|
|
}
|
|
#endif
|
|
/* TODO: support other modes for GLES2 */
|
|
|
|
/* NB: GLES doesn't have glFogi */
|
|
glFogf (GL_FOG_MODE, gl_mode);
|
|
glHint (GL_FOG_HINT, GL_NICEST);
|
|
|
|
glFogf (GL_FOG_DENSITY, (GLfloat) density);
|
|
glFogf (GL_FOG_START, (GLfloat) z_near);
|
|
glFogf (GL_FOG_END, (GLfloat) z_far);
|
|
}
|
|
|
|
void
|
|
cogl_disable_fog (void)
|
|
{
|
|
glDisable (GL_FOG);
|
|
}
|
|
|
|
#if 0
|
|
void
|
|
cogl_flush_gl_state (int flags)
|
|
{
|
|
_cogl_current_matrix_state_flush ();
|
|
}
|
|
#endif
|
|
|
|
void
|
|
cogl_read_pixels (int x,
|
|
int y,
|
|
int width,
|
|
int height,
|
|
CoglReadPixelsFlags source,
|
|
CoglPixelFormat format,
|
|
guint8 *pixels)
|
|
{
|
|
GLint viewport[4];
|
|
GLint viewport_height;
|
|
int rowstride = width * 4;
|
|
guint8 temprow[rowstride];
|
|
|
|
g_return_if_fail (format == COGL_PIXEL_FORMAT_RGBA_8888);
|
|
g_return_if_fail (source == COGL_READ_PIXELS_COLOR_BUFFER);
|
|
|
|
glGetIntegerv (GL_VIEWPORT, viewport);
|
|
viewport_height = viewport[3];
|
|
|
|
/* The y co-ordinate should be given in OpenGL's coordinate system
|
|
so 0 is the bottom row */
|
|
y = viewport_height - y - height;
|
|
|
|
/* Setup the pixel store parameters that may have been changed by
|
|
Cogl */
|
|
glPixelStorei (GL_PACK_ALIGNMENT, 4);
|
|
#ifdef HAVE_COGL_GL
|
|
glPixelStorei (GL_PACK_ROW_LENGTH, 0);
|
|
glPixelStorei (GL_PACK_SKIP_PIXELS, 0);
|
|
glPixelStorei (GL_PACK_SKIP_ROWS, 0);
|
|
#endif /* HAVE_COGL_GL */
|
|
|
|
glReadPixels (x, y, width, height, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
|
|
|
|
/* TODO: consider using the GL_MESA_pack_invert extension in the future
|
|
* to avoid this flip... */
|
|
|
|
/* vertically flip the buffer in-place */
|
|
for (y = 0; y < height / 2; y++)
|
|
{
|
|
if (y != height - y - 1) /* skip center row */
|
|
{
|
|
memcpy (temprow,
|
|
pixels + y * rowstride, rowstride);
|
|
memcpy (pixels + y * rowstride,
|
|
pixels + (height - y - 1) * rowstride, rowstride);
|
|
memcpy (pixels + (height - y - 1) * rowstride,
|
|
temprow,
|
|
rowstride);
|
|
}
|
|
}
|
|
}
|
|
|