medfall

commit ae1b939e6ee51296d7bc15fffaead14ec04d8889
parent 840590e10e0f8c4eb94d8dc4c1b40176d6063cc6
Author: Michael Savage <mikejsavage@gmail.com>
Date:   Sat Nov 26 22:23:40 +0200

Fix skybox

Diffstat:
hm.cc
 | 
5
+++--
skybox.cc
 | 
83
+++++++++++++++++++++++++++++++++++++++++++------------------------------------
skybox.h
 | 
6
++++--
3 files changed, 52 insertions(+), 42 deletions(-)
diff --git a/hm.cc b/hm.cc
@@ -9,6 +9,7 @@
 #include "log.h"
 #include "heightmap.h"
 #include "terrain_manager.h"
+#include "skybox.h"
 #include "work_queue.h"
 #include "stb_truetype.h"
 
@@ -203,7 +204,7 @@ extern "C" GAME_INIT( game_init ) {
 	game->font_at_uv = glGetAttribLocation( game->font_shader, "uv" );
 	game->font_un_atlas = glGetUniformLocation( game->font_shader, "atlas" );
 
-	// skybox_init( &game->skybox );
+	skybox_init( &game->skybox );
 }
 
 static void draw_string( const GameState * game,
@@ -275,8 +276,8 @@ extern "C" GAME_FRAME( game_frame ) {
 	m4 V = camera_to_view( game->pos, game->angles );
 	m4 VP = V * P; // TODO: WTF
 
+	skybox_render( &game->skybox, game->angles, game->test_sun );
 	terrain_render( &game->tm, V, VP, game->test_sun, current_time );
-	// skybox_render( &game->skybox, game->angles );
 
 	glDisable( GL_DEPTH_TEST );
 	glUseProgram( game->test_shader );
diff --git a/skybox.cc b/skybox.cc
@@ -6,49 +6,50 @@
 
 #include "game.h"
 #include "intrinsics.h"
-
-/*
- *  0------1
- *  |`.    |`.    y
- *  |  `2--+---3   \_x
- *  |   |  |   |   |
- *  4---+--5   |   -z
- *   `. |   `. |
- *     `6------7
- */
+#include "skybox.h"
 
 static const char * vert_src = GLSL(
 	in vec3 position;
-
 	out vec3 pos;
 
-	uniform mat3 V;
+	uniform mat4 V;
+	uniform mat4 P;
 
 	void main() {
-		// gl_Position = vec4( ( V * vec4( position, 1.0 ) ).xy, 1.0, 1.0 );
-		gl_Position = vec4( position.xy, 1.0, 1.0 );
-		pos = gl_Position.xyz;
+		gl_Position = P * V * vec4( position, 1.0 );
+		pos = position;
 	}
 );
 
 static const char * frag_src = GLSL(
 	in vec3 pos;
-	out vec4 screen_colour;
+	out vec4 colour;
+
+	uniform float sun;
 
 	void main() {
-		screen_colour = vec4( pos, 1.0 );
+		vec3 sun_direction = normalize( vec3( -1, 0, sun ) );
+
+		vec4 horizon = vec4( 0.4, 0.7, 1.0, 1.0 );
+		vec4 top = vec4( 0.3, 0.6, 1.0, 1.0 );
+		vec4 sunny = vec4( 0.9, 0.9, 0.2, 1.0 );
+
+		float scaled_z = smoothstep( 0.0, 0.2, pos.z );
+		float sun_dot = smoothstep( 0.99, 1.0, dot( sun_direction, normalize( pos ) ) );
+
+		colour = mix( mix( horizon, top, scaled_z ), sunny, sun_dot );
 	}
 );
 
-static glm::vec3 cube_verts[] = {
-	glm::vec3( -1.0f,  1.0f,  1.0f ),
-	glm::vec3(  1.0f,  1.0f,  1.0f ),
-	glm::vec3( -1.0f, -1.0f,  1.0f ),
-	glm::vec3(  1.0f, -1.0f,  1.0f ),
-	glm::vec3( -1.0f,  1.0f, -1.0f ),
-	glm::vec3(  1.0f,  1.0f, -1.0f ),
-	glm::vec3( -1.0f, -1.0f, -1.0f ),
-	glm::vec3(  1.0f, -1.0f, -1.0f ),
+static v3 cube_verts[] = {
+	v3( -1.0f,  1.0f,  1.0f ),
+	v3(  1.0f,  1.0f,  1.0f ),
+	v3( -1.0f, -1.0f,  1.0f ),
+	v3(  1.0f, -1.0f,  1.0f ),
+	v3( -1.0f,  1.0f, -1.0f ),
+	v3(  1.0f,  1.0f, -1.0f ),
+	v3( -1.0f, -1.0f, -1.0f ),
+	v3(  1.0f, -1.0f, -1.0f ),
 };
 
 static GLuint cube_indices[] = { 7, 6, 3, 2, 0, 6, 4, 7, 5, 3, 1, 0, 5, 4 };
@@ -56,7 +57,9 @@ static GLuint cube_indices[] = { 7, 6, 3, 2, 0, 6, 4, 7, 5, 3, 1, 0, 5, 4 };
 void skybox_init( Skybox * skybox ) {
 	skybox->shader = compile_shader( vert_src, frag_src, "screen_colour" );
 	skybox->at_position = glGetAttribLocation( skybox->shader, "position" );
-	skybox->un_v = glGetUniformLocation( skybox->shader, "v" );
+	skybox->un_v = glGetUniformLocation( skybox->shader, "V" );
+	skybox->un_p = glGetUniformLocation( skybox->shader, "P" );
+	skybox->un_sun = glGetUniformLocation( skybox->shader, "sun" );
 
 	glGenVertexArrays( 1, &skybox->vao );
 	glBindVertexArray( skybox->vao );
@@ -74,26 +77,30 @@ void skybox_init( Skybox * skybox ) {
 	glBindVertexArray( 0 );
 }
 
-void skybox_render( const Skybox * skybox, const glm::vec3 & angles ) {
+static glm::mat4 P( glm::perspective( glm::radians( 120.0f ), float( WIDTH ) / float( HEIGHT ), 0.1f, 10000.0f ) );
+
+static m4 angles_to_view( v3 angles ) {
+	return m4_rotz( -angles.y ) * m4_rotx( -angles.x );
+}
+
+void skybox_render( const Skybox * skybox, v3 angles, float sun ) {
+	glDisable( GL_CULL_FACE );
+	glDepthMask( GL_FALSE );
 	glUseProgram( skybox->shader );
 	glBindVertexArray( skybox->vao );
 
-	const glm::mat3 V = glm::mat3( glm::rotate(
-		glm::rotate(
-			glm::mat4(),
-			angles.x,
-			glm::vec3( 1, 0, 0 )
-		),
-		angles.y,
-		glm::vec3( 0, 0, 1 )
-	) );
+	m4 V = angles_to_view( angles );
 
-	glUniformMatrix4fv( skybox->un_v, 1, GL_FALSE, glm::value_ptr( V ) );
+	glUniformMatrix4fv( skybox->un_v, 1, GL_FALSE, ( float * ) &V );
+	glUniformMatrix4fv( skybox->un_p, 1, GL_FALSE, glm::value_ptr( P ) );
+	glUniform1f( skybox->un_sun, sun );
 
 	glDrawElements( GL_TRIANGLE_STRIP, ARRAY_COUNT( cube_indices ), GL_UNSIGNED_INT, 0 );
 
 	glBindVertexArray( 0 );
 	glUseProgram( 0 );
+	glEnable( GL_CULL_FACE );
+	glDepthMask( GL_TRUE );
 }
 
 void skybox_destroy( Skybox * skybox ) {
diff --git a/skybox.h b/skybox.h
@@ -2,12 +2,14 @@
 #define _SKYBOX_H_
 
 #include "glad.h"
-#include <glm/glm.hpp>
+#include "linear_algebra.h"
 
 struct Skybox {
 	GLuint shader;
 	GLuint at_position;
 	GLuint un_v;
+	GLuint un_p;
+	GLuint un_sun;
 
 	GLuint vao;
 	GLuint vbo;
@@ -15,7 +17,7 @@ struct Skybox {
 };
 
 void skybox_init( Skybox * skybox );
-void skybox_render( const Skybox * skybox, const glm::vec3 & angles );
+void skybox_render( const Skybox * skybox, v3 angles, float sun );
 void skybox_destroy( Skybox * skybox );
 
 #endif // _SKYBOX_H_