From 56d6d59869fcdd9d23b0135e3262d9d29c218e05 Mon Sep 17 00:00:00 2001
From: hgn <hgodden00@gmail.com>
Date: Sun, 18 Jul 2021 20:10:40 +0100
Subject: [PATCH] first tile rendering

---
 fishladder.c   | 65 +++++++++++++++++++++++++++++++++++++++++++++-----
 vg/vg.h        | 21 ++++++++++++++++
 vg/vg_shader.h |  6 +++--
 3 files changed, 84 insertions(+), 8 deletions(-)

diff --git a/fishladder.c b/fishladder.c
index e93d666..7f49563 100644
--- a/fishladder.c
+++ b/fishladder.c
@@ -27,32 +27,85 @@ SHADER_DEFINE( colour_shader,
 	UNIFORMS({ "uPvm", "uColour" })
 )
 
+mat4 m_projection;
+mat4 m_view;
+mat4 m_pv;
+
 int main( int argc, char *argv[] )
 {
 	vg_init( argc, argv, "FishLadder" );
 }
 
-void vg_start(void)
-{
-	SHADER_INIT( colour_shader );
-}
-
 void vg_update(void)
 {
+	// Update camera
+	float ratio = (float)vg_window_y / (float)vg_window_x;
+	float const size = 7.5f;
+	glm_ortho( -size, size, -size*ratio, size*ratio, 0.1f, 100.f, m_projection );
 
+	glm_mat4_identity( m_view );
+	glm_translate_z( m_view, -10.f );
+	glm_rotate_x( m_view, -1.0f, m_view );
+	
+	glm_mat4_mul( m_projection, m_view, m_pv );
 }
 
+GLuint tile_vao;
+GLuint tile_vbo;
+
 void vg_render(void)
 {
+	glEnable( GL_DEPTH_TEST );
+	glClearColor( 0.94f, 0.94f, 0.94f, 1.0f );
+	glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
+	
+	SHADER_USE( colour_shader );
+	glUniformMatrix4fv( SHADER_UNIFORM( colour_shader, "uPvm" ), 1, GL_FALSE, (float *)m_pv );
+	glUniform4f( SHADER_UNIFORM( colour_shader, "uColour" ), 0.5f, 0.5f, 0.5f, 1.0f );
 	
+	glBindVertexArray( tile_vao );
+	glDrawArrays( GL_TRIANGLES, 0, 6 );
 }
 
-void vg_ui(void)
+void vg_start(void)
 {
+	SHADER_INIT( colour_shader );
+	
+	glGenVertexArrays( 1, &tile_vao );
+	glGenBuffers( 1, &tile_vbo );
+	
+	float quad_mesh[] =
+	{
+		-0.5f, 0.f, -0.5f,
+		-0.5f, 0.f, 0.5f,
+		 0.5f, 0.f, 0.5f,
+		-0.5f, 0.f, -0.5f,
+		 0.5f, 0.f, 0.5f,
+		 0.5f, 0.f, -0.5f
+	};
+	
+	glBindVertexArray( tile_vao );
+	glBindBuffer( GL_ARRAY_BUFFER, tile_vbo );
+	glBufferData
+	(
+		GL_ARRAY_BUFFER,
+		sizeof( quad_mesh ),
+		quad_mesh,
+		GL_STATIC_DRAW
+	);
+	
+	glVertexAttribPointer( 0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0 );
+	glEnableVertexAttribArray( 0 );
 	
+	VG_CHECK_GL();
 }
 
 void vg_free(void)
 {
 	
 }
+
+void vg_ui(void)
+{
+	
+}
diff --git a/vg/vg.h b/vg/vg.h
index 28aa229..6b4cd23 100644
--- a/vg/vg.h
+++ b/vg/vg.h
@@ -13,6 +13,8 @@
 #define STB_DS_IMPLEMENTATION
 #include "stb/stb_ds.h"
 
+#include "cglm/include/cglm/cglm.h"
+
 void vg_register_exit( void( *funcptr )(void), const char *name );
 void vg_exiterr( const char *strErr );
 
@@ -179,6 +181,23 @@ void vg_update_inputs(void)
 // Engine main
 // ===========================================================================================================
 
+#ifndef VG_RELEASE
+void vg_checkgl( const char *src_info )
+{
+	GLenum err;
+	while( (err = glGetError()) != GL_NO_ERROR )
+	{
+		vg_error( "(%s) OpenGL Error: #%d\n", src_info, err );
+	}
+}
+
+ #define VG_STRINGIT( X ) #X
+ #define VG_CHECK_GL() vg_checkgl( __FILE__ ":L" VG_STRINGIT(__LINE__) )
+#else
+ #define VG_CHECK_GL()
+#endif
+
+
 #define VG_GAMELOOP
 
 void( *vg_on_exit[16] )(void);
@@ -341,6 +360,8 @@ static void vg_init( int argc, char *argv[], const char *window_name )
 			vg_ui();
 			
 			glfwSwapBuffers( vg_window );
+			
+			VG_CHECK_GL();
 		}
 	}
 	
diff --git a/vg/vg_shader.h b/vg/vg_shader.h
index 19c1fc2..ede1b13 100644
--- a/vg/vg_shader.h
+++ b/vg/vg_shader.h
@@ -19,8 +19,10 @@ static inline int static_str_index( const char *list[], int len, const char *str
 }
 #pragma GCC diagnostic pop
 
-#define SHADER_UNIFORM( NAME, U ) NAME##_auto_uniforms[ STR_STATIC_INDEX( NAME##_auto_names, U ) ]
-#define SHADER_UNIFORM_NAME( NAME, UID ) NAME##_auto_names[ UID ]
+#define SHADER_USE( NAME ) glUseProgram( NAME##_static_shader.program )
+
+#define SHADER_UNIFORM( NAME, U ) NAME##_shader_uniforms[ STR_STATIC_INDEX( NAME##_shader_names, U ) ]
+#define SHADER_UNIFORM_NAME( NAME, UID ) NAME##_shader_names[ UID ]
 #define STR_STATIC_INDEX( LIST, STR ) static_str_index( LIST, vg_list_size(LIST), STR )
 
 #define UNIFORMS(...) __VA_ARGS__
-- 
2.25.1