medfall

commit bdbc2921098966d343f0a6b09363e8d32a4dbc0c
parent 7508d242ccf8168171ff7a86e613a7939781d652
Author: Michael Savage <mikejsavage@gmail.com>
Date:   Mon May 15 03:28:22 +0300

Add framebuffers to the renderer

Diffstat:
renderer.cc
 | 
55
+++++++++++++++++++++++++++++++++++++++++++++++++++++++
renderer.h
 | 
19
+++++++++++++++++++
2 files changed, 74 insertions(+), 0 deletions(-)
diff --git a/renderer.cc b/renderer.cc
@@ -11,6 +11,7 @@ STATIC_ASSERT( SAME_TYPE( UB, GLuint ) );
 STATIC_ASSERT( SAME_TYPE( Shader, GLuint ) );
 STATIC_ASSERT( SAME_TYPE( Texture, GLuint ) );
 STATIC_ASSERT( SAME_TYPE( TextureBufferObject, GLuint ) );
+STATIC_ASSERT( SAME_TYPE( FramebufferObject, GLuint ) );
 STATIC_ASSERT( SAME_TYPE( u32, GLuint ) );
 
 static const GLuint ATTR_POSITION = 0;
@@ -60,6 +61,9 @@ static GLenum textureformat_to_glenum( TextureFormat format, bool srgb ) {
 		case TEXFMT_R_U8:
 			ASSERT( !srgb );
 			return GL_R8;
+		case TEXFMT_DEPTH:
+			ASSERT( !srgb );
+			return GL_DEPTH_COMPONENT24;
 		case TEXFMT_BC1:
 			return srgb ? GL_COMPRESSED_SRGB_S3TC_DXT1_EXT : GL_COMPRESSED_RGB_S3TC_DXT1_EXT;
 		case TEXFMT_BC3:
@@ -194,6 +198,47 @@ void renderer_delete_tb( TB tb ) {
 	glDeleteTextures( 1, &tb.texture );
 }
 
+static GLenum framebufferattachment_to_glenum( FramebufferAttachment attachment ) {
+	switch( attachment ) {
+		case FB_COLOR: return GL_COLOR_ATTACHMENT0;
+		case FB_DEPTH: return GL_DEPTH_ATTACHMENT;
+	}
+
+	FATAL( "invalid FramebufferAttachment: {}", attachment );
+	return GL_INVALID_ENUM;
+}
+
+FB renderer_new_fb( TextureConfig texture_config, FramebufferAttachment attachment ) {
+	ASSERT( !is_compressed( texture_config.format ) );
+	return renderer_new_fb( renderer_new_texture( texture_config ), attachment );
+}
+
+FB renderer_new_fb( Texture texture, FramebufferAttachment attachment ) {
+	GLuint fbo;
+
+	glGenFramebuffers( 1, &fbo );
+	glBindFramebuffer( GL_FRAMEBUFFER, fbo );
+	glFramebufferTexture2D( GL_FRAMEBUFFER, framebufferattachment_to_glenum( attachment ), GL_TEXTURE_2D, texture, 0 );
+	glReadBuffer( GL_NONE );
+
+	if( attachment == FB_DEPTH ) {
+		glDrawBuffer( GL_NONE );
+	}
+
+	ASSERT( glCheckFramebufferStatus( GL_FRAMEBUFFER ) == GL_FRAMEBUFFER_COMPLETE );
+	glBindFramebuffer( GL_FRAMEBUFFER, 0 );
+
+	FB fb;
+	fb.fbo = fbo;
+	fb.texture = texture;
+	return fb;
+}
+
+void renderer_delete_fb( FB fb ) {
+	glDeleteBuffers( 1, &fb.fbo );
+	glDeleteTextures( 1, &fb.texture );
+}
+
 static GLuint new_gl_shader( GLenum type, const char * src ) {
 	const char * srcs[] = {
 		"#version 330\n",
@@ -385,6 +430,10 @@ Texture renderer_new_texture( TextureConfig config ) {
 				channels = GL_RED;
 				type = GL_UNSIGNED_BYTE;
 				break;
+			case TEXFMT_DEPTH:
+				channels = GL_DEPTH_COMPONENT;
+				type = GL_FLOAT;
+				break;
 			default:
 				FATAL( "implement channel/type selection for {}", config.format );
 				break;
@@ -573,6 +622,12 @@ void renderer_draw_mesh( const Mesh & mesh, RenderState state ) {
 		}
 	}
 
+	// framebuffer
+	if( state.fb.fbo != previous_render_state.fb.fbo ) {
+		glBindFramebuffer( GL_DRAW_FRAMEBUFFER, state.fb.fbo );
+		glClear( GL_DEPTH_BUFFER_BIT ); // TODO TODO TODO
+	}
+
 	// depth writing
 	if( state.disable_depth_writes != previous_render_state.disable_depth_writes ) {
 		glDepthMask( state.disable_depth_writes ? GL_FALSE : GL_TRUE );
diff --git a/renderer.h b/renderer.h
@@ -14,6 +14,7 @@ typedef u32 UB;
 typedef u32 Shader;
 typedef u32 Texture;
 typedef u32 TextureBufferObject;
+typedef u32 FramebufferObject;
 
 const u32 UB_VS_HOT = 0;
 const u32 UB_VS_COLD = 1;
@@ -46,6 +47,11 @@ struct TB {
 	Texture texture;
 };
 
+struct FB {
+	FramebufferObject fbo;
+	Texture texture;
+};
+
 #define RENDERER_MAX_TEXTURES 4
 #define RENDERER_MAX_TEXTURE_BUFFERS 4
 #define RENDERER_MAX_UBS 4
@@ -54,6 +60,7 @@ struct RenderState {
 	UB ubs[ RENDERER_MAX_UBS ] = { };
 	Texture textures[ RENDERER_MAX_TEXTURES ] = { };
 	TB tbs[ RENDERER_MAX_TEXTURE_BUFFERS ] = { };
+	FB fb = { };
 	Shader shader = INVALID_SHADER;
 	DepthFunc depth_func = DEPTHFUNC_LESS;
 	CullFace cull_face = CULLFACE_BACK;
@@ -126,6 +133,9 @@ enum TextureFormat {
 	TEXFMT_RGB_FLOAT,
 	TEXFMT_R_FLOAT,
 	TEXFMT_R_U8,
+
+	TEXFMT_DEPTH,
+
 	TEXFMT_BC1,
 	TEXFMT_BC3,
 	TEXFMT_BC4,
@@ -154,6 +164,11 @@ struct TextureConfig {
 	bool srgb = false;
 };
 
+enum FramebufferAttachment {
+	FB_COLOR,
+	FB_DEPTH,
+};
+
 enum ClearColourBool { CLEARCOLOUR_DONT, CLEARCOLOUR_DO };
 enum ClearDepthBool { CLEARDEPTH_DONT, CLEARDEPTH_DO };
 
@@ -173,6 +188,10 @@ TB renderer_new_tb( TextureFormat format, const void * data = NULL, u32 len = 0,
 void renderer_tb_data( TB tb, const void * data, u32 len, BufferUsage usage = BUFFERUSAGE_DYNAMIC );
 void renderer_delete_tb( TB ub );
 
+FB renderer_new_fb( TextureConfig texture_format, FramebufferAttachment attachment );
+FB renderer_new_fb( Texture texture, FramebufferAttachment attachment );
+void renderer_delete_fb( FB fb );
+
 Shader renderer_new_shader( ShaderConfig config );
 Shader renderer_new_shader( const char * src );
 void renderer_delete_shader( Shader shader );