mutter/clutter/cogl/gl/cogl.c

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/*
* Clutter COGL
*
* A basic GL/GLES Abstraction/Utility Layer
*
* Authored By Matthew Allum <mallum@openedhand.com>
*
* Copyright (C) 2007 OpenedHand
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include "config.h"
#include "cogl.h"
#include <GL/gl.h>
#include <string.h>
#if G_BYTE_ORDER == G_LITTLE_ENDIAN
#define PIXEL_TYPE GL_UNSIGNED_BYTE
#else
#define PIXEL_TYPE GL_UNSIGNED_INT_8_8_8_8_REV
#endif
static gulong __enable_flags = 0;
#if COGL_DEBUG
struct token_string
{
GLuint Token;
const char *String;
};
static const struct token_string Errors[] = {
{ GL_NO_ERROR, "no error" },
{ GL_INVALID_ENUM, "invalid enumerant" },
{ GL_INVALID_VALUE, "invalid value" },
{ GL_INVALID_OPERATION, "invalid operation" },
{ GL_STACK_OVERFLOW, "stack overflow" },
{ GL_STACK_UNDERFLOW, "stack underflow" },
{ GL_OUT_OF_MEMORY, "out of memory" },
#ifdef GL_INVALID_FRAMEBUFFER_OPERATION_EXT
{ GL_INVALID_FRAMEBUFFER_OPERATION_EXT, "invalid framebuffer operation" },
#endif
{ ~0, NULL }
};
static const char*
error_string(GLenum errorCode)
{
int i;
for (i = 0; Errors[i].String; i++) {
if (Errors[i].Token == errorCode)
return Errors[i].String;
}
return "unknown";
}
#endif
#if COGL_DEBUG
#define GE(x...) G_STMT_START { \
GLenum err; \
(x); \
while ((err = glGetError()) != GL_NO_ERROR) { \
fprintf(stderr, "glError: %s caught at %s:%u\n", \
(char *)error_string(err), \
__FILE__, __LINE__); \
} \
} G_STMT_END
#else
#define GE(x) (x);
#endif
CoglFuncPtr
cogl_get_proc_address (const gchar* name)
{
return NULL;
}
gboolean
cogl_check_extension (const gchar *name, const gchar *ext)
{
return FALSE;
}
void
cogl_paint_init (ClutterColor *color)
{
GE( glClearColor (((float) color->red / 0xff * 1.0),
((float) color->green / 0xff * 1.0),
((float) color->blue / 0xff * 1.0),
0.0) );
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
glDisable (GL_LIGHTING);
glDisable (GL_DEPTH_TEST);
cogl_enable (CGL_ENABLE_BLEND);
glTexEnvi (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
}
/* FIXME: inline most of these */
void
cogl_push_matrix (void)
{
glPushMatrix();
}
void
cogl_pop_matrix (void)
{
glPopMatrix();
}
void
cogl_scale (ClutterFixed x, ClutterFixed y)
{
glScaled (CLUTTER_FIXED_TO_DOUBLE (x),
CLUTTER_FIXED_TO_DOUBLE (y),
1.0);
}
void
cogl_translatex (ClutterFixed x, ClutterFixed y, ClutterFixed z)
{
glTranslated (CLUTTER_FIXED_TO_DOUBLE (x),
CLUTTER_FIXED_TO_DOUBLE (y),
CLUTTER_FIXED_TO_DOUBLE (z));
}
void
cogl_translate (gint x, gint y, gint z)
{
glTranslatef ((float)x, (float)y, (float)z);
}
void
cogl_rotatex (ClutterFixed angle, gint x, gint y, gint z)
{
glRotated (CLUTTER_FIXED_TO_DOUBLE (angle),
CLUTTER_FIXED_TO_DOUBLE (x),
CLUTTER_FIXED_TO_DOUBLE (y),
CLUTTER_FIXED_TO_DOUBLE (z));
}
void
cogl_rotate (gint angle, gint x, gint y, gint z)
{
glRotatef ((float)angle, (float)x, (float)y, (float)z);
}
void
cogl_enable (gulong flags)
{
/* This function essentially caches glEnable state() in the
* hope of lessening number GL traffic.
*/
if (flags & CGL_ENABLE_BLEND)
{
if (!(__enable_flags & CGL_ENABLE_BLEND))
{
glEnable (GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
}
__enable_flags |= CGL_ENABLE_BLEND;
}
else if (__enable_flags & CGL_ENABLE_BLEND)
{
glDisable (GL_BLEND);
__enable_flags &= ~CGL_ENABLE_BLEND;
}
if (flags & CGL_ENABLE_TEXTURE_2D)
{
if (!(__enable_flags & CGL_ENABLE_TEXTURE_2D))
glEnable (GL_TEXTURE_2D);
__enable_flags |= CGL_ENABLE_TEXTURE_2D;
}
else if (__enable_flags & CGL_ENABLE_TEXTURE_2D)
{
glDisable (GL_TEXTURE_2D);
__enable_flags &= ~CGL_ENABLE_TEXTURE_2D;
}
if (flags & CGL_ENABLE_TEXTURE_RECT)
{
if (!(__enable_flags & CGL_ENABLE_TEXTURE_RECT))
glEnable (GL_TEXTURE_RECTANGLE_ARB);
__enable_flags |= CGL_ENABLE_TEXTURE_RECT;
}
else if (__enable_flags & CGL_ENABLE_TEXTURE_RECT)
{
glDisable (GL_TEXTURE_RECTANGLE_ARB);
__enable_flags &= ~CGL_ENABLE_TEXTURE_RECT;
}
if (flags & CGL_ENABLE_ALPHA_TEST)
{
if (!(__enable_flags & CGL_ENABLE_ALPHA_TEST))
glEnable (GL_ALPHA_TEST);
__enable_flags |= CGL_ENABLE_ALPHA_TEST;
}
else if (__enable_flags & CGL_ENABLE_ALPHA_TEST)
{
glDisable (GL_ALPHA_TEST);
__enable_flags &= ~CGL_ENABLE_ALPHA_TEST;
}
}
void
cogl_color (ClutterColor *color)
{
glColor4ub (color->red, color->green, color->blue, color->alpha);
}
gboolean
cogl_texture_can_size (COGLenum pixel_format,
COGLenum pixel_type,
int width,
int height)
{
GLint new_width = 0;
GE( glTexImage2D (GL_PROXY_TEXTURE_2D, 0, GL_RGBA,
width, height, 0 /* border */,
pixel_format, pixel_type, NULL) );
GE( glGetTexLevelParameteriv (GL_PROXY_TEXTURE_2D, 0,
GL_TEXTURE_WIDTH, &new_width) );
return new_width != 0;
}
void
cogl_texture_quad (gint x1,
gint x2,
gint y1,
gint y2,
ClutterFixed tx1,
ClutterFixed ty1,
ClutterFixed tx2,
ClutterFixed ty2)
{
gdouble txf1, tyf1, txf2, tyf2;
txf1 = CLUTTER_FIXED_TO_DOUBLE (tx1);
tyf1 = CLUTTER_FIXED_TO_DOUBLE (ty1);
txf2 = CLUTTER_FIXED_TO_DOUBLE (tx2);
tyf2 = CLUTTER_FIXED_TO_DOUBLE (ty2);
glBegin (GL_QUADS);
glTexCoord2f (txf2, tyf2); glVertex2i (x2, y2);
glTexCoord2f (txf1, tyf2); glVertex2i (x1, y2);
glTexCoord2f (txf1, tyf1); glVertex2i (x1, y1);
glTexCoord2f (txf2, tyf1); glVertex2i (x2, y1);
glEnd ();
}
void
cogl_textures_create (guint num, guint *textures)
{
GE( glGenTextures (num, textures) );
}
void
cogl_textures_destroy (guint num, const guint *textures)
{
GE( glDeleteTextures (num, textures) );
}
void
cogl_texture_bind (COGLenum target, guint texture)
{
GE( glBindTexture (target, texture) );
}
void
cogl_texture_set_alignment (COGLenum target,
guint alignment,
guint row_length)
{
GE( glPixelStorei (GL_UNPACK_ROW_LENGTH, row_length) );
GE( glPixelStorei (GL_UNPACK_ALIGNMENT, alignment) );
}
void
cogl_texture_set_filters (COGLenum target,
COGLenum min_filter,
COGLenum max_filter)
{
GE( glTexParameteri(target, GL_TEXTURE_MAG_FILTER, max_filter) );
GE( glTexParameteri(target, GL_TEXTURE_MIN_FILTER, min_filter) );
}
void
cogl_texture_set_wrap (COGLenum target,
COGLenum wrap_s,
COGLenum wrap_t)
{
GE( glTexParameteri(target, GL_TEXTURE_WRAP_S, wrap_s) );
GE( glTexParameteri(target, GL_TEXTURE_WRAP_T, wrap_s) );
}
void
cogl_texture_image_2d (COGLenum target,
COGLint internal_format,
gint width,
gint height,
COGLenum format,
COGLenum type,
const guchar* pixels)
{
GE( glTexImage2D (target,
0, /* No mipmap support as yet */
internal_format,
width,
height,
0, /* 0 pixel border */
format,
type,
pixels) );
}
void
cogl_texture_sub_image_2d (COGLenum target,
gint xoff,
gint yoff,
gint width,
gint height,
COGLenum format,
COGLenum type,
const guchar* pixels)
{
GE( glTexSubImage2D (target,
0,
xoff,
yoff,
width,
height,
format,
type,
pixels));
}
void
cogl_rectangle (gint x, gint y, guint width, guint height)
{
GE( glRecti (x,y ,width, height) );
}
/* FIXME: Should use ClutterReal or Fixed */
void
cogl_trapezoid (gint y1,
gint x11,
gint x21,
gint y2,
gint x12,
gint x22)
{
GE( glBegin (GL_QUADS) );
GE( glVertex2i (x11, y1) );
GE( glVertex2i (x21, y1) );
GE( glVertex2i (x22, y2) );
GE( glVertex2i (x12, y2) );
GE( glEnd () );
}
void
cogl_alpha_func (COGLenum func,
ClutterFixed ref)
{
GE( glAlphaFunc (func, CLUTTER_FIXED_TO_FLOAT(ref)) );
}
#if 0
/*
* Original floating point implementaiton of the perspective function,
* retained for reference purposes
*/
static inline void
frustum (GLfloat left,
GLfloat right,
GLfloat bottom,
GLfloat top,
GLfloat nearval,
GLfloat farval)
{
GLfloat x, y, a, b, c, d;
GLfloat m[16];
x = (2.0 * nearval) / (right - left);
y = (2.0 * nearval) / (top - bottom);
a = (right + left) / (right - left);
b = (top + bottom) / (top - bottom);
c = -(farval + nearval) / ( farval - nearval);
d = -(2.0 * farval * nearval) / (farval - nearval);
#define M(row,col) m[col*4+row]
M(0,0) = x; M(0,1) = 0.0F; M(0,2) = a; M(0,3) = 0.0F;
M(1,0) = 0.0F; M(1,1) = y; M(1,2) = b; M(1,3) = 0.0F;
M(2,0) = 0.0F; M(2,1) = 0.0F; M(2,2) = c; M(2,3) = d;
M(3,0) = 0.0F; M(3,1) = 0.0F; M(3,2) = -1.0F; M(3,3) = 0.0F;
#undef M
GE( glMultMatrixf (m) );
}
static inline void
perspective (GLfloat fovy,
GLfloat aspect,
GLfloat zNear,
GLfloat zFar)
{
GLfloat xmin, xmax, ymin, ymax;
ymax = zNear * tan (fovy * M_PI / 360.0);
ymin = -ymax;
xmin = ymin * aspect;
xmax = ymax * aspect;
printf ("%f, %f, %f, %f\n", xmin, xmax, ymin, ymax);
frustum (xmin, xmax, ymin, ymax, zNear, zFar);
}
#endif
/*
* Fixed point implementation of the perspective function
*/
void
cogl_perspective (ClutterAngle fovy,
ClutterFixed aspect,
ClutterFixed zNear,
ClutterFixed zFar)
{
ClutterFixed xmax, ymax;
ClutterFixed x, y, c, d;
#ifdef HAVE_COGL_GL
GLfloat m[16];
#else
GLfixed m[16];
#endif
memset (&m[0], 0, sizeof (m));
/*
* Based on the original algorithm in perspective():
*
* 1) xmin = -xmax => xmax + xmin == 0 && xmax - xmin == 2 * xmax
* same true for y, hence: a == 0 && b == 0;
*
* 2) When working with small numbers, we can are loosing significant
* precision, hence we use clutter_qmulx() here, not the fast macro.
*/
ymax = clutter_qmulx (zNear, clutter_tani (fovy >> 1));
xmax = clutter_qmulx (ymax, aspect);
x = CFX_DIV (zNear, xmax);
y = CFX_DIV (zNear, ymax);
c = CFX_DIV (-(zFar + zNear), ( zFar - zNear));
d = CFX_DIV (-(clutter_qmulx (2*zFar, zNear)), (zFar - zNear));
#define M(row,col) m[col*4+row]
#ifdef HAVE_COGL_GL
M(0,0) = CLUTTER_FIXED_TO_FLOAT (x);
M(1,1) = CLUTTER_FIXED_TO_FLOAT (y);
M(2,2) = CLUTTER_FIXED_TO_FLOAT (c);
M(2,3) = CLUTTER_FIXED_TO_FLOAT (d);
M(3,2) = -1.0F;
GE( glMultMatrixf (m) );
#else
M(0,0) = x;
M(1,1) = y;
M(2,2) = c;
M(2,3) = d;
M(3,2) = 1 + ~CFX_ONE;
GE( glMultMatrixx (m) );
#endif
#undef M
}
void
cogl_setup_viewport (guint width,
guint height,
ClutterAngle fovy,
ClutterFixed aspect,
ClutterFixed z_near,
ClutterFixed z_far)
{
GE( glViewport (0, 0, width, height) );
GE( glMatrixMode (GL_PROJECTION) );
GE( glLoadIdentity () );
cogl_perspective (fovy, aspect, z_near, z_far);
GE( glMatrixMode (GL_MODELVIEW) );
GE( glLoadIdentity () );
/* camera distance from screen, 0.5 * tan (FOV) */
#define DEFAULT_Z_CAMERA 0.866025404f
GE( glTranslatef (-0.5f, -0.5f, -DEFAULT_Z_CAMERA) );
GE( glScalef ( 1.0f / width,
-1.0f / height,
1.0f / width) );
GE( glTranslatef (0.0f, -1.0 * height, 0.0f) );
}