# HG changeset patch
# User John Tsiombikas <nuclear@member.fsf.org>
# Date 1349174538 -10800
# Node ID fc2b3d06d07c00daefcc39f77e8b4d9fa17d9922
# Parent  0b130c6e534d6e14562e909311b55a9e83879b34
made the deferred renderer draw into a texture, so that I can reuse the depth
buffer for geometric post effects (particles), and implement other per-pixel
post effects eventually

diff -r 0b130c6e534d -r fc2b3d06d07c prototype/sdr/post.p.glsl
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/prototype/sdr/post.p.glsl	Tue Oct 02 13:42:18 2012 +0300
@@ -0,0 +1,6 @@
+uniform sampler2D fbtex;
+
+void main()
+{
+	gl_FragColor = texture2D(fbtex, gl_TexCoord[0].st);
+}
diff -r 0b130c6e534d -r fc2b3d06d07c prototype/sdr/post.v.glsl
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/prototype/sdr/post.v.glsl	Tue Oct 02 13:42:18 2012 +0300
@@ -0,0 +1,5 @@
+void main()
+{
+	gl_Position = gl_Vertex;
+	gl_TexCoord[0] = gl_MultiTexCoord0;
+}
diff -r 0b130c6e534d -r fc2b3d06d07c prototype/src/renderer_deferred.cc
--- a/prototype/src/renderer_deferred.cc	Tue Oct 02 05:03:26 2012 +0300
+++ b/prototype/src/renderer_deferred.cc	Tue Oct 02 13:42:18 2012 +0300
@@ -9,17 +9,18 @@
 #include "datapath.h"
 
 static unsigned int load_sdr(const char *vfname, const char *pfname);
+static void attach_color_buffer(unsigned int fbo, int count, const unsigned int *tex);
 static int round_pow2(int x);
 
 DeferredRenderer::DeferredRenderer()
 {
-	fbo = rbuf_depth = 0;
+	fbo = rbuf_depth = rend_tex = 0;
 	for(int i=0; i<MRT_COUNT; i++) {
 		mrt_tex[i] = 0;
 	}
 	tex_xsz = tex_ysz = 0;
 
-	mrt_prog = deferred_debug = deferred_omni = 0;
+	mrt_prog = deferred_debug = deferred_omni = post_sdr = 0;
 
 	curr_prog = 0;
 	num_draw_bufs = 1;
@@ -36,10 +37,19 @@
 	if(deferred_debug) {
 		free_program(deferred_debug);
 	}
+	if(post_sdr) {
+		free_program(post_sdr);
+	}
 
 	if(mrt_tex[0]) {
 		glDeleteTextures(MRT_COUNT, mrt_tex);
 	}
+	if(rend_tex) {
+		glDeleteTextures(1, &rend_tex);
+	}
+	if(rbuf_depth) {
+		glDeleteRenderbuffersEXT(1, &rbuf_depth);
+	}
 	if(fbo) {
 		glDeleteFramebuffersEXT(1, &fbo);
 	}
@@ -87,6 +97,10 @@
 		set_uniform_int(deferred_omni, uname, i);
 	}
 
+	if(!(post_sdr = load_sdr("post.v.glsl", "post.p.glsl"))) {
+		return false;
+	}
+
 	rend = this;
 	return true;
 }
@@ -117,6 +131,10 @@
 			glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, tex_xsz, tex_ysz, 0, GL_RGBA, GL_FLOAT, 0);
 		}
 
+		// ... resize the render texture
+		glBindTexture(GL_TEXTURE_2D, rend_tex);
+		glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, tex_xsz, tex_ysz, 0, GL_RGBA, GL_FLOAT, 0);
+
 		// ... resize the depth buffer
 		glBindRenderbufferEXT(GL_RENDERBUFFER, rbuf_depth);
 		glRenderbufferStorageEXT(GL_RENDERBUFFER, GL_DEPTH_COMPONENT, tex_xsz, tex_ysz);
@@ -139,10 +157,13 @@
 	curr_prog = mrt_prog;
 
 	glBindFramebufferEXT(GL_FRAMEBUFFER, fbo);
+	attach_color_buffer(fbo, num_draw_bufs, mrt_tex);
 
 	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 	level->draw();
-	glBindFramebufferEXT(GL_FRAMEBUFFER, 0);
+
+	attach_color_buffer(fbo, 1, &rend_tex);
+	glClear(GL_COLOR_BUFFER_BIT);
 
 	// post-process lighting
 	light_pass(level);
@@ -151,11 +172,30 @@
 	curr_prog = 0;
 
 	render_post(level);
+
+	glBindFramebufferEXT(GL_FRAMEBUFFER, 0);
+
+	// XXX this should be moved to render_post
+	glBindTexture(GL_TEXTURE_2D, rend_tex);
+	glEnable(GL_TEXTURE_2D);
+
+	glUseProgram(post_sdr);
+	glBegin(GL_QUADS);
+	glTexCoord2f(0, 0);
+	glVertex2f(-1, -1);
+	glTexCoord2f((float)width / tex_xsz, 0);
+	glVertex2f(1, -1);
+	glTexCoord2f((float)width / tex_xsz, (float)height / tex_ysz);
+	glVertex2f(1, 1);
+	glTexCoord2f(0, (float)height / tex_ysz);
+	glVertex2f(-1, 1);
+	glEnd();
+	glUseProgram(0);
 }
 
 void DeferredRenderer::light_pass(const Level *level) const
 {
-	glPushAttrib(GL_ENABLE_BIT | GL_POLYGON_BIT);
+	glPushAttrib(GL_ENABLE_BIT | GL_POLYGON_BIT | GL_TEXTURE_BIT);
 
 	glEnable(GL_BLEND);
 	glBlendFunc(GL_ONE, GL_ONE);
@@ -212,6 +252,15 @@
 	glGenFramebuffersEXT(1, &fbo);
 	glBindFramebufferEXT(GL_FRAMEBUFFER, fbo);
 
+	// create the result render target
+	glGenTextures(1, &rend_tex);
+	glBindTexture(GL_TEXTURE_2D, rend_tex);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, clamp);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, clamp);
+	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_RGBA, tex_xsz, tex_ysz, 0, GL_RGBA, GL_FLOAT, 0);
+
 	glGenTextures(MRT_COUNT, mrt_tex);
 	for(int i=0; i<MRT_COUNT; i++) {
 		glBindTexture(GL_TEXTURE_2D, mrt_tex[i]);
@@ -227,16 +276,6 @@
 		CHECKGLERR;
 	}
 
-	if(num_draw_bufs == MRT_COUNT) {
-		static GLenum draw_bufs[] = {
-			GL_COLOR_ATTACHMENT0_EXT, GL_COLOR_ATTACHMENT1_EXT,
-			GL_COLOR_ATTACHMENT2_EXT, GL_COLOR_ATTACHMENT3_EXT,
-			GL_COLOR_ATTACHMENT4_EXT, GL_COLOR_ATTACHMENT5_EXT,
-			GL_COLOR_ATTACHMENT6_EXT, GL_COLOR_ATTACHMENT7_EXT
-		};
-		glDrawBuffersARB(num_draw_bufs, draw_bufs);
-	}
-
 	glGenRenderbuffersEXT(1, &rbuf_depth);
 	glBindRenderbufferEXT(GL_RENDERBUFFER, rbuf_depth);
 	glRenderbufferStorageEXT(GL_RENDERBUFFER, GL_DEPTH_COMPONENT, tex_xsz, tex_ysz);
@@ -270,6 +309,25 @@
 	return prog;
 }
 
+static void attach_color_buffer(unsigned int fbo, int count, const unsigned int *tex)
+{
+	glBindFramebufferEXT(GL_FRAMEBUFFER, fbo);
+
+	for(int i=0; i<count; i++) {
+		GLenum color_att = GL_COLOR_ATTACHMENT0 + i;
+		glFramebufferTexture2DEXT(GL_FRAMEBUFFER, color_att, GL_TEXTURE_2D, tex[i], 0);
+		CHECKGLERR;
+	}
+
+	static GLenum draw_bufs[] = {
+		GL_COLOR_ATTACHMENT0_EXT, GL_COLOR_ATTACHMENT1_EXT,
+		GL_COLOR_ATTACHMENT2_EXT, GL_COLOR_ATTACHMENT3_EXT,
+		GL_COLOR_ATTACHMENT4_EXT, GL_COLOR_ATTACHMENT5_EXT,
+		GL_COLOR_ATTACHMENT6_EXT, GL_COLOR_ATTACHMENT7_EXT
+	};
+	glDrawBuffersARB(count, draw_bufs);
+}
+
 static int round_pow2(int x)
 {
 	x--;
diff -r 0b130c6e534d -r fc2b3d06d07c prototype/src/renderer_deferred.h
--- a/prototype/src/renderer_deferred.h	Tue Oct 02 05:03:26 2012 +0300
+++ b/prototype/src/renderer_deferred.h	Tue Oct 02 13:42:18 2012 +0300
@@ -7,12 +7,15 @@
 
 class DeferredRenderer : public Renderer {
 protected:
-	unsigned int fbo, rbuf_depth;
+	// render targets
+	unsigned int fbo, rend_tex, rbuf_depth;
 	unsigned int mrt_tex[MRT_COUNT];
 	int tex_xsz, tex_ysz;
 
+	// shaders
 	unsigned int mrt_prog;
 	unsigned int deferred_omni, deferred_debug;
+	unsigned int post_sdr;
 
 	mutable unsigned int curr_prog;