medfall

commit 94fd96d9b5d6c0164a3cb93e58c2a60a8addd6b0
parent 8cfe4f3afb92601b49cb74861c67c4d5e69772e9
Author: Michael Savage <mikejsavage@gmail.com>
Date:   Mon Oct 12 12:32:53 +0100

Add lighting (but not shadows) to the BTT renderer

Diffstat:
btt.cc
 | 
19
++++++++++++-------
game.h
 | 
2
++
gpubtt.cc
 | 
24
+++++++++++++++++++++++-
gpubtt.h
 | 
3
++-
4 files changed, 39 insertions(+), 9 deletions(-)
diff --git a/btt.cc b/btt.cc
@@ -15,7 +15,6 @@ static ImmediateContext imm;
 
 static const GLchar * const vert_src = GLSL(
 	in vec3 position;
-	in vec3 normal;
 	in float lit;
 
 	out vec3 n;
@@ -23,10 +22,12 @@ static const GLchar * const vert_src = GLSL(
 	out float l;
 
 	uniform mat4 vp;
+	uniform sampler2D normals;
+	uniform vec2 dimensions;
 
 	void main() {
-		n = normal;
-		l = lit;
+		n = texture( normals, position.xy / dimensions ).xyz;
+		l = lit + 1.0f;
 		gl_Position = vp * vec4( position, 1.0 );
 		depth = gl_Position.z;
 	}
@@ -42,15 +43,17 @@ static const GLchar * frag_src = GLSL(
 	uniform vec3 sun;
 
 	void main() {
+		vec3 normal = normalize( n );
+
 		vec3 ground;
-		if( n.z > 0.9 ) {
+		if( normal.z > 0.9 ) {
 			ground = vec3( 0.4, 1.0, 0.4 );
 		}
 		else {
 			ground = vec3( 0.7, 0.7, 0.5 );
 		}
 
-		float d = max( 0, -dot( n, sun ) );
+		float d = max( 0, -dot( normal, sun ) );
 		float light = max( 0.2, l * d );
 
 		vec3 fog = vec3( 0.6, 0.6, 0.6 );
@@ -217,10 +220,11 @@ extern "C" GAME_INIT( game_init ) {
 
 	state->test_shader = compile_shader( vert_src, frag_src, "screen_colour" );
 	state->test_at_position = glGetAttribLocation( state->test_shader, "position" );
-	state->test_at_normal = glGetAttribLocation( state->test_shader, "normal" );
 	state->test_at_lit = glGetAttribLocation( state->test_shader, "lit" );
 	state->test_un_VP = glGetUniformLocation( state->test_shader, "vp" );
 	state->test_un_sun = glGetUniformLocation( state->test_shader, "sun" );
+	state->test_un_normals = glGetUniformLocation( state->test_shader, "normals" );
+	state->test_un_dimensions = glGetUniformLocation( state->test_shader, "dimensions" );
 
 	state->test_outline_shader = compile_shader( vert_outline_src, frag_outline_src, "screen_colour" );
 	state->test_outline_at_position = glGetAttribLocation( state->test_outline_shader, "position" );
@@ -307,7 +311,8 @@ extern "C" GAME_FRAME( game_frame ) {
 	glUseProgram( state->test_shader );
 	glUniformMatrix4fv( state->test_un_VP, 1, GL_FALSE, glm::value_ptr( VP ) );
 	glUniform3fv( state->test_un_sun, 1, glm::value_ptr( sun ) );
-	gpubtt_render( &state->gpubtt );
+	glUniform2f( state->test_un_dimensions, state->hm.width, state->hm.height );
+	gpubtt_render( &state->gpubtt, state->test_un_normals );
 	glUseProgram( 0 );
 
 	immediate_init( &imm, triangles, array_count( triangles ) );
diff --git a/game.h b/game.h
@@ -111,6 +111,8 @@ struct GameState {
 	GLint test_at_normal;
 	GLint test_at_lit;
 	GLint test_un_sun;
+	GLint test_un_normals;
+	GLint test_un_dimensions;
 
 	GLuint test_outline_shader;
 	GLint test_outline_at_position;
diff --git a/gpubtt.cc b/gpubtt.cc
@@ -67,18 +67,40 @@ void gpubtt_init(
 	glEnableVertexAttribArray( at_position );
 	glVertexAttribPointer( at_position, 3, GL_FLOAT, GL_FALSE, 0, 0 );
 
+	glm::vec3 * const normals = memarena_push_many( mem, glm::vec3, ohm->hm.width * ohm->hm.height );
+
+	for( u32 y = 0; y < ohm->hm.height; y++ ) {
+		for( u32 x = 0; x < ohm->hm.width; x++ ) {
+			const glm::vec3 normal = ohm->hm.point_normal( x, y );
+			normals[ y * ohm->hm.width + x ] = normal;
+		}
+	}
+
+	glGenTextures( 1, &gpubtt->tex_normals );
+	glBindTexture( GL_TEXTURE_2D, gpubtt->tex_normals );
+	glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
+	glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST );
+	glTexImage2D( GL_TEXTURE_2D, 0, GL_RGB, ohm->hm.width, ohm->hm.height, 0, GL_RGB, GL_FLOAT, normals );
+
 	glBindVertexArray( 0 );
 
 	gpubtt->num_verts = i;
 }
 
 void gpubtt_destroy( GPUBTT * const gpubtt ) {
+	glDeleteTextures( 1, &gpubtt->tex_normals );
 	glDeleteBuffers( 1, &gpubtt->vbo_verts );
 	glDeleteVertexArrays( 1, &gpubtt->vao );
 }
 
-void gpubtt_render( const GPUBTT * const gpubtt ) {
+void gpubtt_render( const GPUBTT * const gpubtt, const GLuint un_normals ) {
 	glBindVertexArray( gpubtt->vao );
+
+	glActiveTexture( GL_TEXTURE0 );
+	glBindTexture( GL_TEXTURE_2D, gpubtt->tex_normals );
+	glUniform1i( un_normals, 0 );
+
 	glDrawArrays( GL_TRIANGLES, 0, gpubtt->num_verts * 3 );
+
 	glBindVertexArray( 0 );
 }
diff --git a/gpubtt.h b/gpubtt.h
@@ -9,6 +9,7 @@
 struct GPUBTT {
 	GLuint vao;
 	GLuint vbo_verts;
+	GLuint tex_normals;
 	u32 num_verts;
 };
 
@@ -18,6 +19,6 @@ void gpubtt_init( MemoryArena * const mem, GPUBTT * const gpubtt,
 
 void gpubtt_destroy( GPUBTT * const gpubtt );
 
-void gpubtt_render( const GPUBTT * const gpubtt );
+void gpubtt_render( const GPUBTT * const gpubtt, const GLuint un_normals );
 
 #endif // _GPUBTT_H_