/* * Copyright (C) 1999-2001 Brian Paul All Rights Reserved. * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included * in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ /* * Ported to GLES2. * Kristian Høgsberg * May 3, 2010 * * Improve GLES2 port: * * Refactor gear drawing. * * Use correct normals for surfaces. * * Improve shader. * * Use perspective projection transformation. * * Add FPS count. * * Add comments. * Alexandros Frantzis * Jul 13, 2010 */ #define GL_GLEXT_PROTOTYPES #include #include #include #include #include #include #include #include #include #include #define STRIPS_PER_TOOTH 7 #define VERTICES_PER_TOOTH 34 #define GEAR_VERTEX_STRIDE 6 typedef struct _Data { CoglContext *ctx; CoglFramebuffer *fb; CoglGLES2Context *gles2_ctx; GTimer *timer; int frames; double last_elapsed; } Data; /** * Struct describing the vertices in triangle strip */ struct vertex_strip { /** The first vertex in the strip */ GLint first; /** The number of consecutive vertices in the strip after the first */ GLint count; }; /* Each vertex consist of GEAR_VERTEX_STRIDE GLfloat attributes */ typedef GLfloat GearVertex[GEAR_VERTEX_STRIDE]; /** * Struct representing a gear. */ struct gear { /** The array of vertices comprising the gear */ GearVertex *vertices; /** The number of vertices comprising the gear */ int nvertices; /** The array of triangle strips comprising the gear */ struct vertex_strip *strips; /** The number of triangle strips comprising the gear */ int nstrips; /** The Vertex Buffer Object holding the vertices in the graphics card */ GLuint vbo; }; /** The view rotation [x, y, z] */ static GLfloat view_rot[3] = { 20.0, 30.0, 0.0 }; /** The gears */ static struct gear *gear1, *gear2, *gear3; /** The current gear rotation angle */ static GLfloat angle = 0.0; /** The location of the shader uniforms */ static GLuint ModelViewProjectionMatrix_location, NormalMatrix_location, LightSourcePosition_location, MaterialColor_location; /** The projection matrix */ static GLfloat ProjectionMatrix[16]; /** The direction of the directional light for the scene */ static const GLfloat LightSourcePosition[4] = { 5.0, 5.0, 10.0, 1.0}; /** * Fills a gear vertex. * * @param v the vertex to fill * @param x the x coordinate * @param y the y coordinate * @param z the z coortinate * @param n pointer to the normal table * * @return the operation error code */ static GearVertex * vert (GearVertex *v, GLfloat x, GLfloat y, GLfloat z, GLfloat n[3]) { v[0][0] = x; v[0][1] = y; v[0][2] = z; v[0][3] = n[0]; v[0][4] = n[1]; v[0][5] = n[2]; return v + 1; } /** * Create a gear wheel. * * @param inner_radius radius of hole at center * @param outer_radius radius at center of teeth * @param width width of gear * @param teeth number of teeth * @param tooth_depth depth of tooth * * @return pointer to the constructed struct gear */ static struct gear * create_gear (GLfloat inner_radius, GLfloat outer_radius, GLfloat width, GLint teeth, GLfloat tooth_depth) { GLfloat r0, r1, r2; GLfloat da; GearVertex *v; struct gear *gear; double s[5], c[5]; GLfloat normal[3]; int cur_strip = 0; int i; /* Allocate memory for the gear */ gear = malloc (sizeof *gear); if (gear == NULL) return NULL; /* Calculate the radii used in the gear */ r0 = inner_radius; r1 = outer_radius - tooth_depth / 2.0; r2 = outer_radius + tooth_depth / 2.0; da = 2.0 * M_PI / teeth / 4.0; /* Allocate memory for the triangle strip information */ gear->nstrips = STRIPS_PER_TOOTH * teeth; gear->strips = calloc (gear->nstrips, sizeof (*gear->strips)); /* Allocate memory for the vertices */ gear->vertices = calloc (VERTICES_PER_TOOTH * teeth, sizeof(*gear->vertices)); v = gear->vertices; for (i = 0; i < teeth; i++) { /* Calculate needed sin/cos for varius angles */ sincos (i * 2.0 * M_PI / teeth, &s[0], &c[0]); sincos (i * 2.0 * M_PI / teeth + da, &s[1], &c[1]); sincos (i * 2.0 * M_PI / teeth + da * 2, &s[2], &c[2]); sincos (i * 2.0 * M_PI / teeth + da * 3, &s[3], &c[3]); sincos (i * 2.0 * M_PI / teeth + da * 4, &s[4], &c[4]); /* A set of macros for making the creation of the gears easier */ #define GEAR_POINT(r, da) { (r) * c[(da)], (r) * s[(da)] } #define SET_NORMAL(x, y, z) do { \ normal[0] = (x); normal[1] = (y); normal[2] = (z); \ } while(0) #define GEAR_VERT(v, point, sign) vert((v), p[(point)].x, p[(point)].y, (sign) * width * 0.5, normal) #define START_STRIP do { \ gear->strips[cur_strip].first = v - gear->vertices; \ } while(0); #define END_STRIP do { \ int _tmp = (v - gear->vertices); \ gear->strips[cur_strip].count = _tmp - gear->strips[cur_strip].first; \ cur_strip++; \ } while (0) #define QUAD_WITH_NORMAL(p1, p2) do { \ SET_NORMAL((p[(p1)].y - p[(p2)].y), -(p[(p1)].x - p[(p2)].x), 0); \ v = GEAR_VERT(v, (p1), -1); \ v = GEAR_VERT(v, (p1), 1); \ v = GEAR_VERT(v, (p2), -1); \ v = GEAR_VERT(v, (p2), 1); \ } while(0) { struct point { GLfloat x; GLfloat y; }; /* Create the 7 points (only x,y coords) used to draw a tooth */ struct point p[7] = { GEAR_POINT (r2, 1), // 0 GEAR_POINT (r2, 2), // 1 GEAR_POINT (r1, 0), // 2 GEAR_POINT (r1, 3), // 3 GEAR_POINT (r0, 0), // 4 GEAR_POINT (r1, 4), // 5 GEAR_POINT (r0, 4), // 6 }; /* Front face */ START_STRIP; SET_NORMAL (0, 0, 1.0); v = GEAR_VERT (v, 0, +1); v = GEAR_VERT (v, 1, +1); v = GEAR_VERT (v, 2, +1); v = GEAR_VERT (v, 3, +1); v = GEAR_VERT (v, 4, +1); v = GEAR_VERT (v, 5, +1); v = GEAR_VERT (v, 6, +1); END_STRIP; /* Inner face */ START_STRIP; QUAD_WITH_NORMAL (4, 6); END_STRIP; /* Back face */ START_STRIP; SET_NORMAL (0, 0, -1.0); v = GEAR_VERT (v, 6, -1); v = GEAR_VERT (v, 5, -1); v = GEAR_VERT (v, 4, -1); v = GEAR_VERT (v, 3, -1); v = GEAR_VERT (v, 2, -1); v = GEAR_VERT (v, 1, -1); v = GEAR_VERT (v, 0, -1); END_STRIP; /* Outer face */ START_STRIP; QUAD_WITH_NORMAL (0, 2); END_STRIP; START_STRIP; QUAD_WITH_NORMAL (1, 0); END_STRIP; START_STRIP; QUAD_WITH_NORMAL (3, 1); END_STRIP; START_STRIP; QUAD_WITH_NORMAL (5, 3); END_STRIP; } } gear->nvertices = (v - gear->vertices); /* Store the vertices in a vertex buffer object (VBO) */ glGenBuffers (1, &gear->vbo); glBindBuffer (GL_ARRAY_BUFFER, gear->vbo); glBufferData (GL_ARRAY_BUFFER, gear->nvertices * sizeof(GearVertex), gear->vertices, GL_STATIC_DRAW); return gear; } /** * Multiplies two 4x4 matrices. * * The result is stored in matrix m. * * @param m the first matrix to multiply * @param n the second matrix to multiply */ static void multiply (GLfloat *m, const GLfloat *n) { GLfloat tmp[16]; const GLfloat *row, *column; div_t d; int i, j; for (i = 0; i < 16; i++) { tmp[i] = 0; d = div(i, 4); row = n + d.quot * 4; column = m + d.rem; for (j = 0; j < 4; j++) tmp[i] += row[j] * column[j * 4]; } memcpy (m, &tmp, sizeof tmp); } /** * Rotates a 4x4 matrix. * * @param[in,out] m the matrix to rotate * @param angle the angle to rotate * @param x the x component of the direction to rotate to * @param y the y component of the direction to rotate to * @param z the z component of the direction to rotate to */ static void rotate (GLfloat *m, GLfloat angle, GLfloat x, GLfloat y, GLfloat z) { double s, c; sincos (angle, &s, &c); { GLfloat r[16] = { x * x * (1 - c) + c, y * x * (1 - c) + z * s, x * z * (1 - c) - y * s, 0, x * y * (1 - c) - z * s, y * y * (1 - c) + c, y * z * (1 - c) + x * s, 0, x * z * (1 - c) + y * s, y * z * (1 - c) - x * s, z * z * (1 - c) + c, 0, 0, 0, 0, 1 }; multiply (m, r); } } /** * Translates a 4x4 matrix. * * @param[in,out] m the matrix to translate * @param x the x component of the direction to translate to * @param y the y component of the direction to translate to * @param z the z component of the direction to translate to */ static void translate(GLfloat *m, GLfloat x, GLfloat y, GLfloat z) { GLfloat t[16] = { 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, x, y, z, 1 }; multiply (m, t); } /** * Creates an identity 4x4 matrix. * * @param m the matrix make an identity matrix */ static void identity (GLfloat *m) { GLfloat t[16] = { 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, }; memcpy (m, t, sizeof(t)); } /** * Transposes a 4x4 matrix. * * @param m the matrix to transpose */ static void transpose (GLfloat *m) { GLfloat t[16] = { m[0], m[4], m[8], m[12], m[1], m[5], m[9], m[13], m[2], m[6], m[10], m[14], m[3], m[7], m[11], m[15]}; memcpy (m, t, sizeof(t)); } /** * Inverts a 4x4 matrix. * * This function can currently handle only pure translation-rotation matrices. * Read http://www.gamedev.net/community/forums/topic.asp?topic_id=425118 * for an explanation. */ static void invert (GLfloat *m) { GLfloat t[16]; identity (t); // Extract and invert the translation part 't'. The inverse of a // translation matrix can be calculated by negating the translation // coordinates. t[12] = -m[12]; t[13] = -m[13]; t[14] = -m[14]; // Invert the rotation part 'r'. The inverse of a rotation matrix is // equal to its transpose. m[12] = m[13] = m[14] = 0; transpose (m); // inv (m) = inv (r) * inv (t) multiply (m, t); } /** * Calculate a perspective projection transformation. * * @param m the matrix to save the transformation in * @param fovy the field of view in the y direction * @param aspect the view aspect ratio * @param zNear the near clipping plane * @param zFar the far clipping plane */ static void perspective (GLfloat *m, GLfloat fovy, GLfloat aspect, GLfloat zNear, GLfloat zFar) { GLfloat tmp[16]; double sine, cosine, cotangent, deltaZ; GLfloat radians = fovy / 2 * M_PI / 180; identity (tmp); deltaZ = zFar - zNear; sincos (radians, &sine, &cosine); if ((deltaZ == 0) || (sine == 0) || (aspect == 0)) return; cotangent = cosine / sine; tmp[0] = cotangent / aspect; tmp[5] = cotangent; tmp[10] = -(zFar + zNear) / deltaZ; tmp[11] = -1; tmp[14] = -2 * zNear * zFar / deltaZ; tmp[15] = 0; memcpy (m, tmp, sizeof(tmp)); } /** * Draws a gear. * * @param gear the gear to draw * @param transform the current transformation matrix * @param x the x position to draw the gear at * @param y the y position to draw the gear at * @param angle the rotation angle of the gear * @param color the color of the gear */ static void draw_gear (struct gear *gear, GLfloat *transform, GLfloat x, GLfloat y, GLfloat angle, const GLfloat color[4]) { GLfloat model_view[16]; GLfloat normal_matrix[16]; GLfloat model_view_projection[16]; int n; /* Translate and rotate the gear */ memcpy(model_view, transform, sizeof (model_view)); translate(model_view, x, y, 0); rotate(model_view, 2 * M_PI * angle / 360.0, 0, 0, 1); /* Create and set the ModelViewProjectionMatrix */ memcpy (model_view_projection, ProjectionMatrix, sizeof(model_view_projection)); multiply (model_view_projection, model_view); glUniformMatrix4fv (ModelViewProjectionMatrix_location, 1, GL_FALSE, model_view_projection); /* * Create and set the NormalMatrix. It's the inverse transpose of the * ModelView matrix. */ memcpy (normal_matrix, model_view, sizeof (normal_matrix)); invert (normal_matrix); transpose (normal_matrix); glUniformMatrix4fv (NormalMatrix_location, 1, GL_FALSE, normal_matrix); /* Set the gear color */ glUniform4fv (MaterialColor_location, 1, color); /* Set the vertex buffer object to use */ glBindBuffer (GL_ARRAY_BUFFER, gear->vbo); /* Set up the position of the attributes in the vertex buffer object */ glVertexAttribPointer (0, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(GLfloat), NULL); glVertexAttribPointer (1, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(GLfloat), (GLfloat *) 0 + 3); /* Enable the attributes */ glEnableVertexAttribArray (0); glEnableVertexAttribArray (1); /* Draw the triangle strips that comprise the gear */ for (n = 0; n < gear->nstrips; n++) glDrawArrays (GL_TRIANGLE_STRIP, gear->strips[n].first, gear->strips[n].count); /* Disable the attributes */ glDisableVertexAttribArray (1); glDisableVertexAttribArray (0); } /** * Draws the gears. */ static void gears_draw(void) { const static GLfloat red[4] = { 0.8, 0.1, 0.0, 1.0 }; const static GLfloat green[4] = { 0.0, 0.8, 0.2, 1.0 }; const static GLfloat blue[4] = { 0.2, 0.2, 1.0, 1.0 }; GLfloat transform[16]; identity(transform); glClearColor (0.0, 0.0, 0.0, 0.0); glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); /* Translate and rotate the view */ translate (transform, 0, 0, -20); rotate (transform, 2 * M_PI * view_rot[0] / 360.0, 1, 0, 0); rotate (transform, 2 * M_PI * view_rot[1] / 360.0, 0, 1, 0); rotate (transform, 2 * M_PI * view_rot[2] / 360.0, 0, 0, 1); /* Draw the gears */ draw_gear (gear1, transform, -3.0, -2.0, angle, red); draw_gear (gear2, transform, 3.1, -2.0, -2 * angle - 9.0, green); draw_gear (gear3, transform, -3.1, 4.2, -2 * angle - 25.0, blue); } static gboolean paint_cb (void *user_data) { Data *data = user_data; double elapsed = g_timer_elapsed (data->timer, NULL); double dt = elapsed - data->last_elapsed; CoglError *error = NULL; /* Draw scene with GLES2 */ if (!cogl_push_gles2_context (data->ctx, data->gles2_ctx, data->fb, data->fb, &error)) { g_error ("Failed to push gles2 context: %s\n", error->message); } gears_draw (); cogl_pop_gles2_context (data->ctx); cogl_onscreen_swap_buffers (COGL_ONSCREEN (data->fb)); /* advance rotation for next frame */ angle += 70.0 * dt; /* 70 degrees per second */ if (angle > 3600.0) angle -= 3600.0; data->frames++; if (elapsed > 5.0) { GLfloat fps = data->frames / elapsed; printf ("%d frames in %3.1f seconds = %6.3f FPS\n", data->frames, elapsed, fps); g_timer_reset (data->timer); data->last_elapsed = 0; data->frames = 0; }else data->last_elapsed = elapsed; return FALSE; /* remove the callback */ } static void frame_event_cb (CoglOnscreen *onscreen, CoglFrameEvent event, CoglFrameInfo *info, void *user_data) { if (event == COGL_FRAME_EVENT_SYNC) paint_cb (user_data); } /** * Handles a new window size or exposure. * * @param width the window width * @param height the window height */ static void gears_reshape (int width, int height) { /* Update the projection matrix */ perspective (ProjectionMatrix, 60.0, width / (float)height, 1.0, 1024.0); /* Set the viewport */ glViewport (0, 0, (GLint) width, (GLint) height); } #if 0 /** * Handles special eglut events. * * @param special the event to handle. */ static void gears_special(int special) { switch (special) { case EGLUT_KEY_LEFT: view_rot[1] += 5.0; break; case EGLUT_KEY_RIGHT: view_rot[1] -= 5.0; break; case EGLUT_KEY_UP: view_rot[0] += 5.0; break; case EGLUT_KEY_DOWN: view_rot[0] -= 5.0; break; } } #endif static const char vertex_shader[] = "attribute vec3 position;\n" "attribute vec3 normal;\n" "\n" "uniform mat4 ModelViewProjectionMatrix;\n" "uniform mat4 NormalMatrix;\n" "uniform vec4 LightSourcePosition;\n" "uniform vec4 MaterialColor;\n" "\n" "varying vec4 Color;\n" "\n" "void main(void)\n" "{\n" " // Transform the normal to eye coordinates\n" " vec3 N = normalize(vec3(NormalMatrix * vec4(normal, 1.0)));\n" "\n" " // The LightSourcePosition is actually its direction for directional light\n" " vec3 L = normalize(LightSourcePosition.xyz);\n" "\n" " // Multiply the diffuse value by the vertex color (which is fixed in this case)\n" " // to get the actual color that we will use to draw this vertex with\n" " float diffuse = max(dot(N, L), 0.0);\n" " Color = diffuse * MaterialColor;\n" "\n" " // Transform the position to clip coordinates\n" " gl_Position = ModelViewProjectionMatrix * vec4(position, 1.0);\n" "}"; static const char fragment_shader[] = "precision mediump float;\n" "varying vec4 Color;\n" "\n" "void main(void)\n" "{\n" " gl_FragColor = Color;\n" "}"; static void gears_init(void) { GLuint v, f, program; const char *p; char msg[512]; glEnable (GL_CULL_FACE); glEnable (GL_DEPTH_TEST); /* Compile the vertex shader */ p = vertex_shader; v = glCreateShader (GL_VERTEX_SHADER); glShaderSource (v, 1, &p, NULL); glCompileShader (v); glGetShaderInfoLog (v, sizeof msg, NULL, msg); printf ("vertex shader info: %s\n", msg); /* Compile the fragment shader */ p = fragment_shader; f = glCreateShader (GL_FRAGMENT_SHADER); glShaderSource (f, 1, &p, NULL); glCompileShader (f); glGetShaderInfoLog (f, sizeof msg, NULL, msg); printf ("fragment shader info: %s\n", msg); /* Create and link the shader program */ program = glCreateProgram (); glAttachShader (program, v); glAttachShader (program, f); glBindAttribLocation (program, 0, "position"); glBindAttribLocation (program, 1, "normal"); glLinkProgram (program); glGetProgramInfoLog (program, sizeof msg, NULL, msg); printf ("info: %s\n", msg); /* Enable the shaders */ glUseProgram (program); /* Get the locations of the uniforms so we can access them */ ModelViewProjectionMatrix_location = glGetUniformLocation (program, "ModelViewProjectionMatrix"); NormalMatrix_location = glGetUniformLocation (program, "NormalMatrix"); LightSourcePosition_location = glGetUniformLocation (program, "LightSourcePosition"); MaterialColor_location = glGetUniformLocation (program, "MaterialColor"); /* Set the LightSourcePosition uniform which is constant throughout * the program */ glUniform4fv (LightSourcePosition_location, 1, LightSourcePosition); /* make the gears */ gear1 = create_gear (1.0, 4.0, 1.0, 20, 0.7); gear2 = create_gear (0.5, 2.0, 2.0, 10, 0.7); gear3 = create_gear (1.3, 2.0, 0.5, 10, 0.7); } int main (int argc, char **argv) { Data data; CoglOnscreen *onscreen; CoglError *error = NULL; GSource *cogl_source; GMainLoop *loop; CoglRenderer *renderer; CoglDisplay *display; renderer = cogl_renderer_new (); cogl_renderer_add_constraint (renderer, COGL_RENDERER_CONSTRAINT_SUPPORTS_COGL_GLES2); display = cogl_display_new (renderer, NULL); data.ctx = cogl_context_new (display, NULL); onscreen = cogl_onscreen_new (data.ctx, 300, 300); cogl_onscreen_show (onscreen); data.fb = COGL_FRAMEBUFFER (onscreen); data.gles2_ctx = cogl_gles2_context_new (data.ctx, &error); if (!data.gles2_ctx) g_error ("Failed to create GLES2 context: %s\n", error->message); /* Draw scene with GLES2 */ if (!cogl_push_gles2_context (data.ctx, data.gles2_ctx, data.fb, data.fb, &error)) { g_error ("Failed to push gles2 context: %s\n", error->message); } gears_reshape (cogl_framebuffer_get_width (data.fb), cogl_framebuffer_get_height (data.fb)); /* Initialize the gears */ gears_init(); cogl_pop_gles2_context (data.ctx); cogl_source = cogl_glib_source_new (data.ctx, G_PRIORITY_DEFAULT); g_source_attach (cogl_source, NULL); cogl_onscreen_add_frame_callback (COGL_ONSCREEN (data.fb), frame_event_cb, &data, NULL); /* destroy notify */ g_idle_add (paint_cb, &data); data.timer = g_timer_new (); data.frames = 0; data.last_elapsed = 0; loop = g_main_loop_new (NULL, TRUE); g_main_loop_run (loop); return 0; }