Check for EXT_framebuffer_object before using FBOs

git-svn-id: svn://cook.msm.cam.ac.uk:745/thrust3d/thrust3d@55 84d2e878-0bd5-11dd-ad15-13eda11d74c5

1 files changed, 82 insertions, 69 deletions

diff --git a/src/render.c b/src/render.c
index 4c51496..d8ca276 100644
--- a/src/render.c
+++ b/src/render.c
@@ -158,36 +158,42 @@ RenderContext *render_setup(int width, int height) {
 	glEnable(GL_BLEND);
 	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 	
-	/* Create a small FBO for rendering reflections with */
-	glGenFramebuffersEXT(1, &r->fbo);
-	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, r->fbo);
- 	/* Add a (texture) colour buffer to the FBO */
-	glGenTextures(1, &r->fbotex);
-	glBindTexture(GL_TEXTURE_2D, r->fbotex);
-	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
-	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
-	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, 128, 128, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);
-	glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, r->fbotex, 0);
-	/* Add a depth buffer to the FBO */
-	glGenRenderbuffersEXT(1, &r->fbodepth);
-	glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, r->fbodepth);
-	glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_STENCIL_EXT, 128, 128);
-	glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT, GL_RENDERBUFFER_EXT, r->fbodepth);
-	glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_STENCIL_ATTACHMENT_EXT, GL_RENDERBUFFER_EXT, r->fbodepth);
-	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
-	
-	/* FBO for rendering swirlyness */
-	glGenFramebuffersEXT(1, &r->swirly_fbo);
-	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, r->swirly_fbo);
- 	/* Add a (texture) colour buffer to the FBO */
-	glGenTextures(1, &r->swirly_texture);
-	glBindTexture(GL_TEXTURE_2D, r->swirly_texture);
-	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
-	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
-	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, 128, 128, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);
-	glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, r->swirly_texture, 0);
-	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
-	
+	if ( GLEW_EXT_framebuffer_object ) {
+	
+		/* Create a small FBO for rendering reflections with */
+		glGenFramebuffersEXT(1, &r->fbo);
+		glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, r->fbo);
+	 	/* Add a (texture) colour buffer to the FBO */
+		glGenTextures(1, &r->fbotex);
+		glBindTexture(GL_TEXTURE_2D, r->fbotex);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+		glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, 128, 128, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);
+		glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, r->fbotex, 0);
+		/* Add a depth buffer to the FBO */
+		glGenRenderbuffersEXT(1, &r->fbodepth);
+		glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, r->fbodepth);
+		glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_STENCIL_EXT, 128, 128);
+		glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT, GL_RENDERBUFFER_EXT, r->fbodepth);
+		glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_STENCIL_ATTACHMENT_EXT, GL_RENDERBUFFER_EXT, r->fbodepth);
+		glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
+	
+		/* FBO for rendering swirlyness */
+		glGenFramebuffersEXT(1, &r->swirly_fbo);
+		glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, r->swirly_fbo);
+	 	/* Add a (texture) colour buffer to the FBO */
+		glGenTextures(1, &r->swirly_texture);
+		glBindTexture(GL_TEXTURE_2D, r->swirly_texture);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+		glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, 128, 128, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);
+		glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, r->swirly_texture, 0);
+		glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
+		
+	} else {
+		fprintf(stderr, "EXT_framebuffer_object not supported\n");
+	}
+		
 	/* Create coordinates for a hemisphere to reuse later */
 	r->hemisphere_v = malloc(3*HEMI_NUM_VERTICES*sizeof(GLfloat));
 	r->hemisphere_n = malloc(3*HEMI_NUM_VERTICES*sizeof(GLfloat));
@@ -359,12 +365,14 @@ static int render_model_instance_draw(ModelInstance *instance, Uint32 t, RenderC
 			glNormalPointer(GL_FLOAT, 0, r->hemisphere_n);
 			glTexCoordPointer(2, GL_FLOAT, 0, r->hemisphere_t);
 			
-			glBindTexture(GL_TEXTURE_2D, r->fbotex);
-			glEnable(GL_TEXTURE_2D);
-			glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
+			if ( GLEW_EXT_framebuffer_object ) {
+				glBindTexture(GL_TEXTURE_2D, r->fbotex);
+				glEnable(GL_TEXTURE_2D);
+				glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
+				glUniform1iARB(glGetUniformLocationARB(r->lighting_program, "texture_enabled"), 1);
+				glUniform1iARB(glGetUniformLocationARB(r->lighting_program, "texture_emits"), 1);
+			}
 			
-			glUniform1iARB(glGetUniformLocationARB(r->lighting_program, "texture_enabled"), 1);
-			glUniform1iARB(glGetUniformLocationARB(r->lighting_program, "texture_emits"), 1);
 			glDrawArrays(GL_QUADS, 0, HEMI_NUM_VERTICES);
 			*nvert += HEMI_NUM_VERTICES;
 			glUniform1iARB(glGetUniformLocationARB(r->lighting_program, "texture_emits"), 0);
@@ -589,43 +597,48 @@ void render_draw(Game *game, Uint32 t) {
 	RenderContext *r;
 	
 	r = game->render;
+
+	if ( GLEW_EXT_framebuffer_object ) {
+		
+		/* First pass: Looking upwards */
+		glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, r->fbo);
+		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+		glViewport(0, 0, 256, 256);
+		glMatrixMode(GL_PROJECTION);
+		glLoadIdentity();
+		gluPerspective(70.0, 1.0, 0.1, 80.0);
+		glMatrixMode(GL_MODELVIEW);
+		glLoadIdentity();
+		gluLookAt(game->lander->x, game->lander->y, game->lander->z,
+			  game->lander->x, game->lander->y, game->lander->z+10.0,
+			  sqrtf(2.0)*sinf(game->lander->yaw), sqrtf(2.0)*cosf(game->lander->yaw), 0.0);
+		render_setup_lighting(game);
+		GLfloat amb[] = { 0.1, 0.1, 0.1, 1.0 };
+		glLightModelfv(GL_LIGHT_MODEL_AMBIENT, amb);
+		render_draw_stuff(game, t);
+	
+		/* Render some swirlyness */
+		glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, r->swirly_fbo);
+		glClear(GL_COLOR_BUFFER_BIT);
+		glViewport(0, 0, 128, 128);
+		glUseProgramObjectARB(r->swirly_program);
+		glUniform1fARB(glGetUniformLocationARB(game->render->swirly_program, "time"), t);
+		glMatrixMode(GL_PROJECTION);
+		glLoadIdentity();
+		glMatrixMode(GL_MODELVIEW);
+		glLoadIdentity();
+		glBegin(GL_QUADS);
+			glVertex2f(-1.0, -1.0);
+			glVertex2f(+1.0, -1.0);
+			glVertex2f(+1.0, +1.0);
+			glVertex2f(-1.0, +1.0);
+		glEnd();
+	
+		glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
 	
-	/* First pass: Looking upwards */
-	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, r->fbo);
-	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-	glViewport(0, 0, 256, 256);
-	glMatrixMode(GL_PROJECTION);
-	glLoadIdentity();
-	gluPerspective(70.0, 1.0, 0.1, 80.0);
-	glMatrixMode(GL_MODELVIEW);
-	glLoadIdentity();
-	gluLookAt(game->lander->x, game->lander->y, game->lander->z,
-		  game->lander->x, game->lander->y, game->lander->z+10.0,
-		  sqrtf(2.0)*sinf(game->lander->yaw), sqrtf(2.0)*cosf(game->lander->yaw), 0.0);
-	render_setup_lighting(game);
-	GLfloat amb[] = { 0.1, 0.1, 0.1, 1.0 };
-	glLightModelfv(GL_LIGHT_MODEL_AMBIENT, amb);
-	render_draw_stuff(game, t);
-	
-	/* Render some swirlyness */
-	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, r->swirly_fbo);
-	glClear(GL_COLOR_BUFFER_BIT);
-	glViewport(0, 0, 128, 128);
-	glUseProgramObjectARB(r->swirly_program);
-	glUniform1fARB(glGetUniformLocationARB(game->render->swirly_program, "time"), t);
-	glMatrixMode(GL_PROJECTION);
-	glLoadIdentity();
-	glMatrixMode(GL_MODELVIEW);
-	glLoadIdentity();
-	glBegin(GL_QUADS);
-		glVertex2f(-1.0, -1.0);
-		glVertex2f(+1.0, -1.0);
-		glVertex2f(+1.0, +1.0);
-		glVertex2f(-1.0, +1.0);
-	glEnd();
+	}
 	
 	/* Second pass: Main view */
-	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
 	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 	glViewport(0, 0, r->width, r->height);
 	glMatrixMode(GL_PROJECTION);