From 643420376e22d72d62a34b00f6b3d4c3e6eca979 Mon Sep 17 00:00:00 2001 From: Ludovic Pouzenc Date: Mon, 2 Sep 2019 21:18:37 +0200 Subject: First try for GL drawing. Scene 00 cannot render after scene01_init. --- examples/opengl3_hello.c | 199 ----------------------------------------------- 1 file changed, 199 deletions(-) delete mode 100644 examples/opengl3_hello.c (limited to 'examples') 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 -#include - -#include - -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; -} - -- cgit v1.2.3