medfall

commit 2ea9a2a3c2f58c8578c15c9c71d167d7d1486212
parent b825d9fab38b6e43e54beff7822ea1ce57456044
Author: Michael Savage <mikejsavage@gmail.com>
Date:   Fri Sep  2 15:43:12 -0700

Better font shader

Diffstat:
game.h
 | 
6
++++++
hm.cc
 | 
42
+++++++++++++++++++++++++++++++++++++++---
2 files changed, 45 insertions(+), 3 deletions(-)
diff --git a/game.h b/game.h
@@ -114,6 +114,12 @@ struct GameState {
 	GLint test_at_colour;
 	GLint test_un_VP;
 
+	GLuint font_shader;
+	GLint font_at_position;
+	GLint font_at_colour;
+	GLint font_at_uv;
+	GLint font_un_atlas;
+
 	GLuint test_tex_shader;
 	GLint test_tex_at_pos;
 	GLint test_tex_at_colour;
diff --git a/hm.cc b/hm.cc
@@ -65,6 +65,35 @@ static const GLchar * textured_frag_src = GLSL(
 	}
 );
 
+static const GLchar * const font_vert_src = GLSL(
+	in vec3 position;
+	in vec4 colour;
+	in vec2 uv;
+
+	out vec4 frag_colour;
+	out vec2 frag_uv;
+
+	void main() {
+		gl_Position = vec4( position, 1.0 );
+		frag_colour = colour;
+		frag_uv = uv;
+	}
+);
+
+static const GLchar * font_frag_src = GLSL(
+	in vec4 frag_colour;
+	in vec2 frag_uv;
+
+	uniform sampler2D atlas;
+
+	out vec4 screen_colour;
+
+	void main() {
+		float r = texture( atlas, frag_uv ).r;
+		screen_colour = vec4( frag_colour.rgb, frag_colour.a * r );
+	}
+);
+
 glm::vec3 angles_to_vector( const glm::vec3 & angles ) {
 	return glm::vec3(
 		-sin( angles.y ) * sin( angles.x ),
@@ -170,12 +199,18 @@ extern "C" GAME_INIT( game_init ) {
 	state->test_tex_at_colour = glGetAttribLocation( state->test_tex_shader, "colour" );
 	state->test_tex_at_uv = glGetAttribLocation( state->test_tex_shader, "uv" );
 	state->test_tex_un_tex = glGetUniformLocation( state->test_tex_shader, "tex" );
+
+	state->font_shader = compile_shader( font_vert_src, font_frag_src, "screen_colour" );
+	state->font_at_position = glGetAttribLocation( state->font_shader, "position" );
+	state->font_at_colour = glGetAttribLocation( state->font_shader, "colour" );
+	state->font_at_uv = glGetAttribLocation( state->font_shader, "uv" );
+	state->font_un_atlas = glGetUniformLocation( state->font_shader, "atlas" );
 }
 
 static void draw_string( const GameState * state,
 	float x, float y,
 	const char * str,
-	const GLint at_pos, const GLint at_colour, const GLint at_uv, const GLint un_tex
+	const GLint at_pos, const GLint at_colour, const GLint at_uv, const GLint un_atlas
 ) {
 	const float scale = 1.0f / 32.0f / 5.0f;
 	const glm::vec4 white( 1, 1, 1, 1 );
@@ -201,7 +236,7 @@ static void draw_string( const GameState * state,
 		str++;
 	}
 
-	immediate_render( &imm, at_pos, at_colour, true, at_uv, un_tex );
+	immediate_render( &imm, at_pos, at_colour, true, at_uv, un_atlas );
 
 	glBindTexture( GL_TEXTURE_2D, 0 );
 }
@@ -293,8 +328,9 @@ extern "C" GAME_FRAME( game_frame ) {
 	glDeleteTextures( 1, &tex );
 	glBindTexture( GL_TEXTURE_2D, 0 );
 
+	glUseProgram( state->font_shader );
 	// TODO: the positions don't make sense
-	draw_string( state, -140, -100, "hello", state->test_tex_at_pos, state->test_tex_at_colour, state->test_tex_at_uv, state->test_tex_un_tex );
+	draw_string( state, -140, -100, "hello", state->font_at_position, state->font_at_colour, state->font_at_uv, state->font_un_atlas );
 
 	glUseProgram( 0 );
 	glDisable( GL_BLEND );