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authorLudovic Pouzenc <ludovic@pouzenc.fr>2019-09-02 21:18:37 +0200
committerLudovic Pouzenc <ludovic@pouzenc.fr>2019-09-02 21:18:37 +0200
commit643420376e22d72d62a34b00f6b3d4c3e6eca979 (patch)
tree49434e8d58463c9f349a2b8241cf8abc376f98e2 /examples
parent235cbc46a64ac63fd53df8a39a8681a8fcea2848 (diff)
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First try for GL drawing. Scene 00 cannot render after scene01_init.
Diffstat (limited to 'examples')
-rw-r--r--examples/opengl3_hello.c199
1 files changed, 0 insertions, 199 deletions
diff --git a/examples/opengl3_hello.c b/examples/opengl3_hello.c
deleted file mode 100644
index 7cc9070..0000000
--- a/examples/opengl3_hello.c
+++ /dev/null
@@ -1,199 +0,0 @@
-/*
- Minimal SDL2 + OpenGL3 example.
-
- Author: https://github.com/koute
-
- This file is in the public domain; you can do whatever you want with it.
- In case the concept of public domain doesn't exist in your jurisdiction
- you can also use this code under the terms of Creative Commons CC0 license,
- either version 1.0 or (at your option) any later version; for details see:
- http://creativecommons.org/publicdomain/zero/1.0/
-
- This software is distributed without any warranty whatsoever.
-
- Compile and run with: gcc opengl3_hello.c `sdl2-config --libs --cflags` -lGL -Wall && ./a.out
-*/
-
-#define GL_GLEXT_PROTOTYPES
-
-#include <SDL.h>
-#include <SDL_opengl.h>
-
-#include <stdio.h>
-
-typedef float t_mat4x4[16];
-
-static inline void mat4x4_ortho( t_mat4x4 out, float left, float right, float bottom, float top, float znear, float zfar )
-{
- #define T(a, b) (a * 4 + b)
-
- out[T(0,0)] = 2.0f / (right - left);
- out[T(0,1)] = 0.0f;
- out[T(0,2)] = 0.0f;
- out[T(0,3)] = 0.0f;
-
- out[T(1,1)] = 2.0f / (top - bottom);
- out[T(1,0)] = 0.0f;
- out[T(1,2)] = 0.0f;
- out[T(1,3)] = 0.0f;
-
- out[T(2,2)] = -2.0f / (zfar - znear);
- out[T(2,0)] = 0.0f;
- out[T(2,1)] = 0.0f;
- out[T(2,3)] = 0.0f;
-
- out[T(3,0)] = -(right + left) / (right - left);
- out[T(3,1)] = -(top + bottom) / (top - bottom);
- out[T(3,2)] = -(zfar + znear) / (zfar - znear);
- out[T(3,3)] = 1.0f;
-
- #undef T
-}
-
-static const char * vertex_shader =
- "#version 130\n"
- "in vec2 i_position;\n"
- "in vec4 i_color;\n"
- "out vec4 v_color;\n"
- "uniform mat4 u_projection_matrix;\n"
- "void main() {\n"
- " v_color = i_color;\n"
- " gl_Position = u_projection_matrix * vec4( i_position, 0.0, 1.0 );\n"
- "}\n";
-
-static const char * fragment_shader =
- "#version 130\n"
- "in vec4 v_color;\n"
- "out vec4 o_color;\n"
- "void main() {\n"
- " o_color = v_color;\n"
- "}\n";
-
-typedef enum t_attrib_id
-{
- attrib_position,
- attrib_color
-} t_attrib_id;
-
-int main( int argc, char * argv[] )
-{
- SDL_Init( SDL_INIT_VIDEO );
- SDL_GL_SetAttribute( SDL_GL_DOUBLEBUFFER, 1 );
- SDL_GL_SetAttribute( SDL_GL_ACCELERATED_VISUAL, 1 );
- SDL_GL_SetAttribute( SDL_GL_RED_SIZE, 8 );
- SDL_GL_SetAttribute( SDL_GL_GREEN_SIZE, 8 );
- SDL_GL_SetAttribute( SDL_GL_BLUE_SIZE, 8 );
- SDL_GL_SetAttribute( SDL_GL_ALPHA_SIZE, 8 );
-
- SDL_GL_SetAttribute( SDL_GL_CONTEXT_MAJOR_VERSION, 3 );
- SDL_GL_SetAttribute( SDL_GL_CONTEXT_MINOR_VERSION, 2 );
- SDL_GL_SetAttribute( SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE );
-
- static const int width = 800;
- static const int height = 600;
-
- SDL_Window * window = SDL_CreateWindow( "", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, width, height, SDL_WINDOW_OPENGL | SDL_WINDOW_SHOWN );
- SDL_GLContext context = SDL_GL_CreateContext( window );
-
- GLuint vs, fs, program;
-
- vs = glCreateShader( GL_VERTEX_SHADER );
- fs = glCreateShader( GL_FRAGMENT_SHADER );
-
- int length = strlen( vertex_shader );
- glShaderSource( vs, 1, ( const GLchar ** )&vertex_shader, &length );
- glCompileShader( vs );
-
- GLint status;
- glGetShaderiv( vs, GL_COMPILE_STATUS, &status );
- if( status == GL_FALSE )
- {
- fprintf( stderr, "vertex shader compilation failed\n" );
- return 1;
- }
-
- length = strlen( fragment_shader );
- glShaderSource( fs, 1, ( const GLchar ** )&fragment_shader, &length );
- glCompileShader( fs );
-
- glGetShaderiv( fs, GL_COMPILE_STATUS, &status );
- if( status == GL_FALSE )
- {
- fprintf( stderr, "fragment shader compilation failed\n" );
- return 1;
- }
-
- program = glCreateProgram();
- glAttachShader( program, vs );
- glAttachShader( program, fs );
-
- glBindAttribLocation( program, attrib_position, "i_position" );
- glBindAttribLocation( program, attrib_color, "i_color" );
- glLinkProgram( program );
-
- glUseProgram( program );
-
- glDisable( GL_DEPTH_TEST );
- glClearColor( 0.5, 0.0, 0.0, 0.0 );
- glViewport( 0, 0, width, height );
-
- GLuint vao, vbo;
-
- glGenVertexArrays( 1, &vao );
- glGenBuffers( 1, &vbo );
- glBindVertexArray( vao );
- glBindBuffer( GL_ARRAY_BUFFER, vbo );
-
- glEnableVertexAttribArray( attrib_position );
- glEnableVertexAttribArray( attrib_color );
-
- glVertexAttribPointer( attrib_color, 4, GL_FLOAT, GL_FALSE, sizeof( float ) * 6, 0 );
- glVertexAttribPointer( attrib_position, 2, GL_FLOAT, GL_FALSE, sizeof( float ) * 6, ( void * )(4 * sizeof(float)) );
-
- const GLfloat g_vertex_buffer_data[] = {
- /* R, G, B, A, X, Y */
- 1, 0, 0, 1, 0, 0,
- 0, 1, 0, 1, width, 0,
- 0, 0, 1, 1, width, height,
-
- 1, 0, 0, 1, 0, 0,
- 0, 0, 1, 1, width, height,
- 1, 1, 1, 1, 0, height
- };
-
- glBufferData( GL_ARRAY_BUFFER, sizeof( g_vertex_buffer_data ), g_vertex_buffer_data, GL_STATIC_DRAW );
-
- t_mat4x4 projection_matrix;
- mat4x4_ortho( projection_matrix, 0.0f, (float)width, (float)height, 0.0f, 0.0f, 100.0f );
- glUniformMatrix4fv( glGetUniformLocation( program, "u_projection_matrix" ), 1, GL_FALSE, projection_matrix );
-
- for( ;; )
- {
- glClear( GL_COLOR_BUFFER_BIT );
-
- SDL_Event event;
- while( SDL_PollEvent( &event ) )
- {
- switch( event.type )
- {
- case SDL_KEYUP:
- if( event.key.keysym.sym == SDLK_ESCAPE )
- return 0;
- break;
- }
- }
-
- glBindVertexArray( vao );
- glDrawArrays( GL_TRIANGLES, 0, 6 );
-
- SDL_GL_SwapWindow( window );
- SDL_Delay( 1 );
- }
-
- SDL_GL_DeleteContext( context );
- SDL_DestroyWindow( window );
- SDL_Quit();
-
- return 0;
-}
-