Make render use a FBO then upscale in a separate step. Requires GL 2.0 for now.

1 files changed, 143 insertions, 4 deletions

diff --git a/render-gl.c b/render-gl.c
index 82ff219..71a52bb 100644
--- a/render-gl.c
+++ b/render-gl.c
@@ -23,8 +23,8 @@
 static GLuint atlas_texture, palette_texture, page_coor_texture,
               page_colour_texture, page_hoff_texture;
 static GLuint tile_fragment_program, page_fragment_program;
-static GLuint display_list;
-
+static GLuint render_tex;
+static GLuint render_fb;
 
 #define error() do { int err = glGetError(); if (err) fatal("GL error 0x%04x at line %d\n", err, __LINE__); } while(0)
 
@@ -53,7 +53,8 @@ static enum render_state {
 	state_nothing,
 	state_page,
 	state_tile,
-	state_rect
+	state_rect,
+	state_final
 } current_render_state;
 
 static void set_render_state(enum render_state render_state)
@@ -72,6 +73,9 @@ static void set_render_state(enum render_state render_state)
 		glActiveTexture(GL_TEXTURE0);
 		glBindTexture(GL_TEXTURE_2D, atlas_texture);
 		glEnable(GL_TEXTURE_2D);
+		glActiveTexture(GL_TEXTURE1);
+		glBindTexture(GL_TEXTURE_1D, palette_texture);
+		glEnable(GL_TEXTURE_1D);
 		glActiveTexture(GL_TEXTURE2);
 		glEnable(GL_TEXTURE_2D);
 		glActiveTexture(GL_TEXTURE3);
@@ -86,6 +90,9 @@ static void set_render_state(enum render_state render_state)
 		glActiveTexture(GL_TEXTURE0);
 		glBindTexture(GL_TEXTURE_2D, atlas_texture);
 		glEnable(GL_TEXTURE_2D);
+		glActiveTexture(GL_TEXTURE1);
+		glBindTexture(GL_TEXTURE_1D, palette_texture);
+		glEnable(GL_TEXTURE_1D);
 		glActiveTexture(GL_TEXTURE2);
 		glDisable(GL_TEXTURE_2D);
 		glActiveTexture(GL_TEXTURE3);
@@ -98,13 +105,33 @@ static void set_render_state(enum render_state render_state)
 		glDisable(GL_FRAGMENT_PROGRAM_ARB);
 		glActiveTexture(GL_TEXTURE0);
 		glDisable(GL_TEXTURE_2D);
+		glActiveTexture(GL_TEXTURE1);
+		glDisable(GL_TEXTURE_1D);
+		glActiveTexture(GL_TEXTURE2);
+		glDisable(GL_TEXTURE_2D);
+		glActiveTexture(GL_TEXTURE3);
+		glDisable(GL_TEXTURE_2D);
+		glActiveTexture(GL_TEXTURE4);
+		glDisable(GL_TEXTURE_1D);
+		break;
+
+	case state_final:
+		glDisable(GL_FRAGMENT_PROGRAM_ARB);
+		glColor3ub(255,255,255);
+		glActiveTexture(GL_TEXTURE0);
+		glBindTexture(GL_TEXTURE_2D, render_tex);
+		glEnable(GL_TEXTURE_2D);
+		glActiveTexture(GL_TEXTURE1);
+		glDisable(GL_TEXTURE_1D);
 		glActiveTexture(GL_TEXTURE2);
 		glDisable(GL_TEXTURE_2D);
 		glActiveTexture(GL_TEXTURE3);
 		glDisable(GL_TEXTURE_2D);
 		glActiveTexture(GL_TEXTURE4);
 		glDisable(GL_TEXTURE_1D);
+		break;
 	}
+
 }
 
 
@@ -238,14 +265,31 @@ error();
 
 void render_begin(void)
 {
+	glBindFramebuffer(GL_FRAMEBUFFER, render_fb);
+	glDrawBuffer(GL_COLOR_ATTACHMENT0);
 	glClearColor(0, 0, 0, 0);
 	glClear(GL_COLOR_BUFFER_BIT);
 
+	glViewport(0, 0, 320, 240);
+
 	set_render_state(state_nothing);
 }
 
+
+
 void render_end(void)
 {
+	glBindFramebuffer(GL_FRAMEBUFFER, 0);
+	glViewport(0, 0, 320*3, 240*3);
+
+	set_render_state(state_final);
+	glDisable(GL_CULL_FACE);
+	glBegin(GL_QUADS);
+	glTexCoord2f(0.0, 1.0); glVertex2f(0.0, 0.0);
+	glTexCoord2f(1.0, 1.0); glVertex2f(320.0, 0.0);
+	glTexCoord2f(1.0, 0.0); glVertex2f(320.0, 240.0);
+	glTexCoord2f(0.0, 0.0); glVertex2f(0.0, 240.0);
+	glEnd();
 }
 
 
@@ -409,6 +453,92 @@ static void init_fragment_programs(void)
 	init_fragment_program(&page_fragment_program, page_frag);
 }
 
+#ifdef GLSL
+static void init_glsl_programs(void)
+{
+	const char tile_frag[] =
+		"uniform sampler2D tile; \n"
+		"uniform sampler1D palette; \n"
+		"main() \n"
+		"{ \n"
+		"	float index = texture2D(tile, gl_TexCoord[0]); \n"
+		"	index += gl_Color.r; \n"
+		"	vec4 color = texture1D(palette, index); \n"
+		"	color.a *= gl_Color.a; \n"
+		"	gl_FragColor = color; \n"
+		"} \n";
+/*
+		"!!ARBfp1.0\n"
+		"OPTION ARB_precision_hint_nicest; \n"
+
+		"TEMP r0; \n"
+
+		"TEX r0.x, fragment.texcoord[0], texture[0], 2D; \n"
+		"ADD r0.x, r0.x, fragment.color.r; \n"
+
+		"TEX r0, r0, texture[1], 1D; \n"		
+		"MUL r0.a, r0.a, fragment.color.a; \n"
+		"MOV result.color, r0; \n"
+
+		"END";*/
+	init_glsl_program(&tile_glsl_program, tile_frag);
+
+	const char page_frag[] =
+		"uniform sampler2D tile; \n"
+		"uniform sampler1D palette; \n"
+		"uniform vec2 local0; \n"
+		"uniform vec2 local1; \n"
+		"uniform vec2 local2; \n"
+		"main() \n"
+		"{ \n"
+		"	float hoff = texture1D(hoff_texture, gl_TexCoord[0]); \n"
+		"	vec2 coor = gl_TexCoord[0].xy; \n"
+		"	coor.y += hoff; \n"
+		"	coor = coor.yxxx * local1 + local0; \n"
+		"	vec2 tile_coor = floor(coor) * vec2(1.0/64.0, 1.0/32.0); \n"
+		"	vec2 tile = texture2D(tile_coor, gl_TexCoord[0]); \n"
+		"	vec2 atlas_coor = frac(coor) *local2 + tile.xyyy; \n"
+		"	vec2 tile = texture2D(tile_coor, gl_TexCoord[0]); \n"
+		"} \n";
+
+/*
+		"!!ARBfp1.0\n"
+		"OPTION ARB_precision_hint_nicest; \n"
+
+		"TEMP coor, tile_coor, tile, tile_colour; \n"
+		"TEMP atlas_coor, palette_coor, colour, hoff; \n"
+
+		"TEX hoff, fragment.texcoord[0], texture[4], 1D; \n"
+
+		"MOV coor, fragment.texcoord[0]; \n"
+		"ADD coor.y, coor, hoff; \n"
+		"MAD coor, coor.yxxx, program.local[1], program.local[0]; \n"
+		// now coor is integer tile #, fraction coor within tile
+
+		"FLR tile_coor, coor; \n"
+		"FRC atlas_coor, coor; \n"
+
+		// 1/64,1/32
+		"PARAM tile_scale = { 0.015625, 0.03125 }; \n"
+		"MUL tile_coor, tile_coor, tile_scale; \n"
+
+		"TEX tile, tile_coor, texture[2], 2D; \n"	
+		"TEX tile_colour, tile_coor, texture[3], 2D; \n"
+		"MAD atlas_coor, atlas_coor, program.local[2], tile.xwww; \n"
+
+		"TEX palette_coor, atlas_coor, texture[0], 2D; \n"	
+		"ADD palette_coor, palette_coor, tile_colour.r; \n"
+
+		"TEX colour, palette_coor, texture[1], 1D; \n"		
+		"MUL colour.a, colour.a, tile_colour.a; \n"
+		"MOV result.color, colour; \n"
+
+		"END";
+*/
+	init_glsl_program(&page_fragment_program, page_frag);
+}
+#endif
+
 void render_init(u32 pixel_size)
 {
 	printf("GL RENDERER: %s\n", glGetString(GL_RENDERER));
@@ -427,10 +557,19 @@ void render_init(u32 pixel_size)
 
 	glEnable(GL_BLEND);
 	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+
+	glGenTextures(1,&render_tex);
+	glGenFramebuffers(1, &render_fb);
+	glBindFramebuffer(GL_FRAMEBUFFER, render_fb);
+	glBindTexture(GL_TEXTURE_2D, render_tex);
+	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB8, 320, 240, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL);
+	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, render_tex, 0);
+
 	error();
 
 	init_textures();
 	init_fragment_programs();
 
-	display_list = glGenLists(1);
 }