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author | Lorenzo Torres <lorenzotorres@outlook.it> | 2025-03-12 19:56:19 +0100 |
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committer | Lorenzo Torres <lorenzotorres@outlook.it> | 2025-03-12 19:56:19 +0100 |
commit | 4f45899a3c28440724ffcaa3a604ad48f18a25c8 (patch) | |
tree | cecd79da4e3e3cb17ffd86ec1a58d6e77a44cb83 /ext/glfw/examples/triangle-opengles.c | |
parent | fc39b277155044366f1647b238a415fab4028d83 (diff) |
base code
Diffstat (limited to 'ext/glfw/examples/triangle-opengles.c')
-rw-r--r-- | ext/glfw/examples/triangle-opengles.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/ext/glfw/examples/triangle-opengles.c b/ext/glfw/examples/triangle-opengles.c new file mode 100644 index 0000000..03eb026 --- /dev/null +++ b/ext/glfw/examples/triangle-opengles.c @@ -0,0 +1,170 @@ +//======================================================================== +// OpenGL ES 2.0 triangle example +// Copyright (c) Camilla Löwy <elmindreda@glfw.org> +// +// This software is provided 'as-is', without any express or implied +// warranty. In no event will the authors be held liable for any damages +// arising from the use of this software. +// +// Permission is granted to anyone to use this software for any purpose, +// including commercial applications, and to alter it and redistribute it +// freely, subject to the following restrictions: +// +// 1. The origin of this software must not be misrepresented; you must not +// claim that you wrote the original software. If you use this software +// in a product, an acknowledgment in the product documentation would +// be appreciated but is not required. +// +// 2. Altered source versions must be plainly marked as such, and must not +// be misrepresented as being the original software. +// +// 3. This notice may not be removed or altered from any source +// distribution. +// +//======================================================================== + +#define GLAD_GLES2_IMPLEMENTATION +#include <glad/gles2.h> +#define GLFW_INCLUDE_NONE +#include <GLFW/glfw3.h> + +#include "linmath.h" + +#include <stdlib.h> +#include <stddef.h> +#include <stdio.h> + +typedef struct Vertex +{ + vec2 pos; + vec3 col; +} Vertex; + +static const Vertex vertices[3] = +{ + { { -0.6f, -0.4f }, { 1.f, 0.f, 0.f } }, + { { 0.6f, -0.4f }, { 0.f, 1.f, 0.f } }, + { { 0.f, 0.6f }, { 0.f, 0.f, 1.f } } +}; + +static const char* vertex_shader_text = +"#version 100\n" +"precision mediump float;\n" +"uniform mat4 MVP;\n" +"attribute vec3 vCol;\n" +"attribute vec2 vPos;\n" +"varying vec3 color;\n" +"void main()\n" +"{\n" +" gl_Position = MVP * vec4(vPos, 0.0, 1.0);\n" +" color = vCol;\n" +"}\n"; + +static const char* fragment_shader_text = +"#version 100\n" +"precision mediump float;\n" +"varying vec3 color;\n" +"void main()\n" +"{\n" +" gl_FragColor = vec4(color, 1.0);\n" +"}\n"; + +static void error_callback(int error, const char* description) +{ + fprintf(stderr, "GLFW Error: %s\n", description); +} + +static void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods) +{ + if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS) + glfwSetWindowShouldClose(window, GLFW_TRUE); +} + +int main(void) +{ + glfwSetErrorCallback(error_callback); + + if (!glfwInit()) + exit(EXIT_FAILURE); + + glfwWindowHint(GLFW_CLIENT_API, GLFW_OPENGL_ES_API); + glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 2); + glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0); + glfwWindowHint(GLFW_CONTEXT_CREATION_API, GLFW_EGL_CONTEXT_API); + + GLFWwindow* window = glfwCreateWindow(640, 480, "OpenGL ES 2.0 Triangle (EGL)", NULL, NULL); + if (!window) + { + glfwWindowHint(GLFW_CONTEXT_CREATION_API, GLFW_NATIVE_CONTEXT_API); + window = glfwCreateWindow(640, 480, "OpenGL ES 2.0 Triangle", NULL, NULL); + if (!window) + { + glfwTerminate(); + exit(EXIT_FAILURE); + } + } + + glfwSetKeyCallback(window, key_callback); + + glfwMakeContextCurrent(window); + gladLoadGLES2(glfwGetProcAddress); + glfwSwapInterval(1); + + GLuint vertex_buffer; + glGenBuffers(1, &vertex_buffer); + glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer); + glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW); + + const GLuint vertex_shader = glCreateShader(GL_VERTEX_SHADER); + glShaderSource(vertex_shader, 1, &vertex_shader_text, NULL); + glCompileShader(vertex_shader); + + const GLuint fragment_shader = glCreateShader(GL_FRAGMENT_SHADER); + glShaderSource(fragment_shader, 1, &fragment_shader_text, NULL); + glCompileShader(fragment_shader); + + const GLuint program = glCreateProgram(); + glAttachShader(program, vertex_shader); + glAttachShader(program, fragment_shader); + glLinkProgram(program); + + const GLint mvp_location = glGetUniformLocation(program, "MVP"); + const GLint vpos_location = glGetAttribLocation(program, "vPos"); + const GLint vcol_location = glGetAttribLocation(program, "vCol"); + + glEnableVertexAttribArray(vpos_location); + glEnableVertexAttribArray(vcol_location); + glVertexAttribPointer(vpos_location, 2, GL_FLOAT, GL_FALSE, + sizeof(Vertex), (void*) offsetof(Vertex, pos)); + glVertexAttribPointer(vcol_location, 3, GL_FLOAT, GL_FALSE, + sizeof(Vertex), (void*) offsetof(Vertex, col)); + + while (!glfwWindowShouldClose(window)) + { + int width, height; + glfwGetFramebufferSize(window, &width, &height); + const float ratio = width / (float) height; + + glViewport(0, 0, width, height); + glClear(GL_COLOR_BUFFER_BIT); + + mat4x4 m, p, mvp; + mat4x4_identity(m); + mat4x4_rotate_Z(m, m, (float) glfwGetTime()); + mat4x4_ortho(p, -ratio, ratio, -1.f, 1.f, 1.f, -1.f); + mat4x4_mul(mvp, p, m); + + glUseProgram(program); + glUniformMatrix4fv(mvp_location, 1, GL_FALSE, (const GLfloat*) &mvp); + glDrawArrays(GL_TRIANGLES, 0, 3); + + glfwSwapBuffers(window); + glfwPollEvents(); + } + + glfwDestroyWindow(window); + + glfwTerminate(); + exit(EXIT_SUCCESS); +} + |