medfall

commit d8d8867c136613e8be91b76894b3e1711f852595
parent 758e00f61b4e288a2a8f7c6e9b9bcf8574b08226
Author: Michael Savage <mikejsavage@gmail.com>
Date:   Sat Dec  3 22:21:27 +0200

Add alpha blending to the renderer

Diffstat:
hm.cc
 | 
4
----
renderer.cc
 | 
9
+++++++++
renderer.h
 | 
1
+
text_renderer.cc
 | 
5
+++--
4 files changed, 13 insertions(+), 6 deletions(-)
diff --git a/hm.cc b/hm.cc
@@ -180,8 +180,6 @@ extern "C" GAME_FRAME( game_frame ) {
 	immediate_render_state.depth_func = DEPTHFUNC_DISABLED;
 	immediate_render( &game->test_immediate, immediate_render_state );
 
-	glEnable( GL_BLEND );
-	glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
 	ImmediateContext imm;
 	ImmediateTriangle asdf[ 32 ];
 	immediate_init( &imm, asdf, 32 );
@@ -191,6 +189,4 @@ extern "C" GAME_FRAME( game_frame ) {
 		snprintf( buf, sizeof( buf ), "Frame time: %.1fms FPS: %.1f", dt * 1000.0f, 1.0f / dt );
 		draw_text( buf, 2.0f, 2.0f, 16.0f );
 	}
-
-	glDisable( GL_BLEND );
 }
diff --git a/renderer.cc b/renderer.cc
@@ -501,6 +501,15 @@ void renderer_draw_mesh( const Mesh & mesh, RenderState state ) {
 		glDepthFunc( depthfunc_to_glenum( state.depth_func ) );
 	}
 
+	// alpha blending
+	if( state.enable_alpha_blending ) {
+		glEnable( GL_BLEND );
+		glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
+	}
+	else {
+		glDisable( GL_BLEND );
+	}
+
 	// TODO: missing a bunch of stuff here
 
 	GLenum primitive = primitivetype_to_glenum( mesh.primitive_type );
diff --git a/renderer.h b/renderer.h
@@ -68,6 +68,7 @@ struct RenderState {
 	CullFace cull_face;
 	bool disable_depth_writes;
 	bool disable_colour_writes;
+	bool enable_alpha_blending;
 };
 
 enum PrimitiveType {
diff --git a/text_renderer.cc b/text_renderer.cc
@@ -33,8 +33,8 @@ static const char * frag_src = GLSL(
 	out vec4 screen_colour;
 
 	void main() {
-		float r = texture( atlas, frag_uv ).r;
-		screen_colour = vec4( frag_colour.rgb, frag_colour.a * r );
+		float alpha = texture( atlas, frag_uv ).r;
+		screen_colour = vec4( frag_colour.rgb, frag_colour.a * alpha );
 	}
 );
 
@@ -152,6 +152,7 @@ void draw_text( const char * str, float x, float y, float pixel_size ) {
 	render_state.shader = shader;
 	render_state.textures[ 0 ] = sizes[ size_idx ].atlas;
 	render_state.depth_func = DEPTHFUNC_DISABLED;
+	render_state.enable_alpha_blending = true;
 	// render_state.disable_depth_writes = true;
 
 	immediate_render( &imm, render_state );