From 5a1275f661f2d879411411a1376b790f8aec7947 Mon Sep 17 00:00:00 2001 From: sanine Date: Sun, 21 Aug 2022 20:27:25 -0500 Subject: add glfw library --- libs/glfw-3.3.8/examples/sharing.c | 234 +++++++++++++++++++++++++++++++++++++ 1 file changed, 234 insertions(+) create mode 100644 libs/glfw-3.3.8/examples/sharing.c (limited to 'libs/glfw-3.3.8/examples/sharing.c') diff --git a/libs/glfw-3.3.8/examples/sharing.c b/libs/glfw-3.3.8/examples/sharing.c new file mode 100644 index 0000000..4a1a232 --- /dev/null +++ b/libs/glfw-3.3.8/examples/sharing.c @@ -0,0 +1,234 @@ +//======================================================================== +// Context sharing example +// Copyright (c) Camilla Löwy +// +// 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. +// +//======================================================================== + +#include +#define GLFW_INCLUDE_NONE +#include + +#include +#include + +#include "getopt.h" +#include "linmath.h" + +static const char* vertex_shader_text = +"#version 110\n" +"uniform mat4 MVP;\n" +"attribute vec2 vPos;\n" +"varying vec2 texcoord;\n" +"void main()\n" +"{\n" +" gl_Position = MVP * vec4(vPos, 0.0, 1.0);\n" +" texcoord = vPos;\n" +"}\n"; + +static const char* fragment_shader_text = +"#version 110\n" +"uniform sampler2D texture;\n" +"uniform vec3 color;\n" +"varying vec2 texcoord;\n" +"void main()\n" +"{\n" +" gl_FragColor = vec4(color * texture2D(texture, texcoord).rgb, 1.0);\n" +"}\n"; + +static const vec2 vertices[4] = +{ + { 0.f, 0.f }, + { 1.f, 0.f }, + { 1.f, 1.f }, + { 0.f, 1.f } +}; + +static void error_callback(int error, const char* description) +{ + fprintf(stderr, "Error: %s\n", description); +} + +static void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods) +{ + if (action == GLFW_PRESS && key == GLFW_KEY_ESCAPE) + glfwSetWindowShouldClose(window, GLFW_TRUE); +} + +int main(int argc, char** argv) +{ + GLFWwindow* windows[2]; + GLuint texture, program, vertex_buffer; + GLint mvp_location, vpos_location, color_location, texture_location; + + glfwSetErrorCallback(error_callback); + + if (!glfwInit()) + exit(EXIT_FAILURE); + + glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 2); + glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0); + + windows[0] = glfwCreateWindow(400, 400, "First", NULL, NULL); + if (!windows[0]) + { + glfwTerminate(); + exit(EXIT_FAILURE); + } + + glfwSetKeyCallback(windows[0], key_callback); + + glfwMakeContextCurrent(windows[0]); + + // Only enable vsync for the first of the windows to be swapped to + // avoid waiting out the interval for each window + glfwSwapInterval(1); + + // The contexts are created with the same APIs so the function + // pointers should be re-usable between them + gladLoadGL(glfwGetProcAddress); + + // Create the OpenGL objects inside the first context, created above + // All objects will be shared with the second context, created below + { + int x, y; + char pixels[16 * 16]; + GLuint vertex_shader, fragment_shader; + + glGenTextures(1, &texture); + glBindTexture(GL_TEXTURE_2D, texture); + + srand((unsigned int) glfwGetTimerValue()); + + for (y = 0; y < 16; y++) + { + for (x = 0; x < 16; x++) + pixels[y * 16 + x] = rand() % 256; + } + + glTexImage2D(GL_TEXTURE_2D, 0, GL_LUMINANCE, 16, 16, 0, GL_LUMINANCE, GL_UNSIGNED_BYTE, pixels); + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); + + vertex_shader = glCreateShader(GL_VERTEX_SHADER); + glShaderSource(vertex_shader, 1, &vertex_shader_text, NULL); + glCompileShader(vertex_shader); + + fragment_shader = glCreateShader(GL_FRAGMENT_SHADER); + glShaderSource(fragment_shader, 1, &fragment_shader_text, NULL); + glCompileShader(fragment_shader); + + program = glCreateProgram(); + glAttachShader(program, vertex_shader); + glAttachShader(program, fragment_shader); + glLinkProgram(program); + + mvp_location = glGetUniformLocation(program, "MVP"); + color_location = glGetUniformLocation(program, "color"); + texture_location = glGetUniformLocation(program, "texture"); + vpos_location = glGetAttribLocation(program, "vPos"); + + glGenBuffers(1, &vertex_buffer); + glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer); + glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW); + } + + glUseProgram(program); + glUniform1i(texture_location, 0); + + glEnable(GL_TEXTURE_2D); + glBindTexture(GL_TEXTURE_2D, texture); + + glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer); + glEnableVertexAttribArray(vpos_location); + glVertexAttribPointer(vpos_location, 2, GL_FLOAT, GL_FALSE, + sizeof(vertices[0]), (void*) 0); + + windows[1] = glfwCreateWindow(400, 400, "Second", NULL, windows[0]); + if (!windows[1]) + { + glfwTerminate(); + exit(EXIT_FAILURE); + } + + // Place the second window to the right of the first + { + int xpos, ypos, left, right, width; + + glfwGetWindowSize(windows[0], &width, NULL); + glfwGetWindowFrameSize(windows[0], &left, NULL, &right, NULL); + glfwGetWindowPos(windows[0], &xpos, &ypos); + + glfwSetWindowPos(windows[1], xpos + width + left + right, ypos); + } + + glfwSetKeyCallback(windows[1], key_callback); + + glfwMakeContextCurrent(windows[1]); + + // While objects are shared, the global context state is not and will + // need to be set up for each context + + glUseProgram(program); + + glEnable(GL_TEXTURE_2D); + glBindTexture(GL_TEXTURE_2D, texture); + + glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer); + glEnableVertexAttribArray(vpos_location); + glVertexAttribPointer(vpos_location, 2, GL_FLOAT, GL_FALSE, + sizeof(vertices[0]), (void*) 0); + + while (!glfwWindowShouldClose(windows[0]) && + !glfwWindowShouldClose(windows[1])) + { + int i; + const vec3 colors[2] = + { + { 0.8f, 0.4f, 1.f }, + { 0.3f, 0.4f, 1.f } + }; + + for (i = 0; i < 2; i++) + { + int width, height; + mat4x4 mvp; + + glfwGetFramebufferSize(windows[i], &width, &height); + glfwMakeContextCurrent(windows[i]); + + glViewport(0, 0, width, height); + + mat4x4_ortho(mvp, 0.f, 1.f, 0.f, 1.f, 0.f, 1.f); + glUniformMatrix4fv(mvp_location, 1, GL_FALSE, (const GLfloat*) mvp); + glUniform3fv(color_location, 1, colors[i]); + glDrawArrays(GL_TRIANGLE_FAN, 0, 4); + + glfwSwapBuffers(windows[i]); + } + + glfwWaitEvents(); + } + + glfwTerminate(); + exit(EXIT_SUCCESS); +} + -- cgit v1.2.1