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Diffstat (limited to '3rdparty/glfw/source/examples/heightmap.c')
| -rw-r--r-- | 3rdparty/glfw/source/examples/heightmap.c | 513 |
1 files changed, 0 insertions, 513 deletions
diff --git a/3rdparty/glfw/source/examples/heightmap.c b/3rdparty/glfw/source/examples/heightmap.c deleted file mode 100644 index ad5d47c..0000000 --- a/3rdparty/glfw/source/examples/heightmap.c +++ /dev/null @@ -1,513 +0,0 @@ -//======================================================================== -// Heightmap example program using OpenGL 3 core profile -// Copyright (c) 2010 Olivier Delannoy -// -// 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 <stdlib.h> -#include <stdio.h> -#include <math.h> -#include <assert.h> -#include <stddef.h> - -#define GLAD_GL_IMPLEMENTATION -#include <glad/gl.h> -#define GLFW_INCLUDE_NONE -#include <GLFW/glfw3.h> - -/* Map height updates */ -#define MAX_CIRCLE_SIZE (5.0f) -#define MAX_DISPLACEMENT (1.0f) -#define DISPLACEMENT_SIGN_LIMIT (0.3f) -#define MAX_ITER (200) -#define NUM_ITER_AT_A_TIME (1) - -/* Map general information */ -#define MAP_SIZE (10.0f) -#define MAP_NUM_VERTICES (80) -#define MAP_NUM_TOTAL_VERTICES (MAP_NUM_VERTICES*MAP_NUM_VERTICES) -#define MAP_NUM_LINES (3* (MAP_NUM_VERTICES - 1) * (MAP_NUM_VERTICES - 1) + \ - 2 * (MAP_NUM_VERTICES - 1)) - - -/********************************************************************** - * Default shader programs - *********************************************************************/ - -static const char* vertex_shader_text = -"#version 150\n" -"uniform mat4 project;\n" -"uniform mat4 modelview;\n" -"in float x;\n" -"in float y;\n" -"in float z;\n" -"\n" -"void main()\n" -"{\n" -" gl_Position = project * modelview * vec4(x, y, z, 1.0);\n" -"}\n"; - -static const char* fragment_shader_text = -"#version 150\n" -"out vec4 color;\n" -"void main()\n" -"{\n" -" color = vec4(0.2, 1.0, 0.2, 1.0); \n" -"}\n"; - -/********************************************************************** - * Values for shader uniforms - *********************************************************************/ - -/* Frustum configuration */ -static GLfloat view_angle = 45.0f; -static GLfloat aspect_ratio = 4.0f/3.0f; -static GLfloat z_near = 1.0f; -static GLfloat z_far = 100.f; - -/* Projection matrix */ -static GLfloat projection_matrix[16] = { - 1.0f, 0.0f, 0.0f, 0.0f, - 0.0f, 1.0f, 0.0f, 0.0f, - 0.0f, 0.0f, 1.0f, 0.0f, - 0.0f, 0.0f, 0.0f, 1.0f -}; - -/* Model view matrix */ -static GLfloat modelview_matrix[16] = { - 1.0f, 0.0f, 0.0f, 0.0f, - 0.0f, 1.0f, 0.0f, 0.0f, - 0.0f, 0.0f, 1.0f, 0.0f, - 0.0f, 0.0f, 0.0f, 1.0f -}; - -/********************************************************************** - * Heightmap vertex and index data - *********************************************************************/ - -static GLfloat map_vertices[3][MAP_NUM_TOTAL_VERTICES]; -static GLuint map_line_indices[2*MAP_NUM_LINES]; - -/* Store uniform location for the shaders - * Those values are setup as part of the process of creating - * the shader program. They should not be used before creating - * the program. - */ -static GLuint mesh; -static GLuint mesh_vbo[4]; - -/********************************************************************** - * OpenGL helper functions - *********************************************************************/ - -/* Creates a shader object of the specified type using the specified text - */ -static GLuint make_shader(GLenum type, const char* text) -{ - GLuint shader; - GLint shader_ok; - GLsizei log_length; - char info_log[8192]; - - shader = glCreateShader(type); - if (shader != 0) - { - glShaderSource(shader, 1, (const GLchar**)&text, NULL); - glCompileShader(shader); - glGetShaderiv(shader, GL_COMPILE_STATUS, &shader_ok); - if (shader_ok != GL_TRUE) - { - fprintf(stderr, "ERROR: Failed to compile %s shader\n", (type == GL_FRAGMENT_SHADER) ? "fragment" : "vertex" ); - glGetShaderInfoLog(shader, 8192, &log_length,info_log); - fprintf(stderr, "ERROR: \n%s\n\n", info_log); - glDeleteShader(shader); - shader = 0; - } - } - return shader; -} - -/* Creates a program object using the specified vertex and fragment text - */ -static GLuint make_shader_program(const char* vs_text, const char* fs_text) -{ - GLuint program = 0u; - GLint program_ok; - GLuint vertex_shader = 0u; - GLuint fragment_shader = 0u; - GLsizei log_length; - char info_log[8192]; - - vertex_shader = make_shader(GL_VERTEX_SHADER, vs_text); - if (vertex_shader != 0u) - { - fragment_shader = make_shader(GL_FRAGMENT_SHADER, fs_text); - if (fragment_shader != 0u) - { - /* make the program that connect the two shader and link it */ - program = glCreateProgram(); - if (program != 0u) - { - /* attach both shader and link */ - glAttachShader(program, vertex_shader); - glAttachShader(program, fragment_shader); - glLinkProgram(program); - glGetProgramiv(program, GL_LINK_STATUS, &program_ok); - - if (program_ok != GL_TRUE) - { - fprintf(stderr, "ERROR, failed to link shader program\n"); - glGetProgramInfoLog(program, 8192, &log_length, info_log); - fprintf(stderr, "ERROR: \n%s\n\n", info_log); - glDeleteProgram(program); - glDeleteShader(fragment_shader); - glDeleteShader(vertex_shader); - program = 0u; - } - } - } - else - { - fprintf(stderr, "ERROR: Unable to load fragment shader\n"); - glDeleteShader(vertex_shader); - } - } - else - { - fprintf(stderr, "ERROR: Unable to load vertex shader\n"); - } - return program; -} - -/********************************************************************** - * Geometry creation functions - *********************************************************************/ - -/* Generate vertices and indices for the heightmap - */ -static void init_map(void) -{ - int i; - int j; - int k; - GLfloat step = MAP_SIZE / (MAP_NUM_VERTICES - 1); - GLfloat x = 0.0f; - GLfloat z = 0.0f; - /* Create a flat grid */ - k = 0; - for (i = 0 ; i < MAP_NUM_VERTICES ; ++i) - { - for (j = 0 ; j < MAP_NUM_VERTICES ; ++j) - { - map_vertices[0][k] = x; - map_vertices[1][k] = 0.0f; - map_vertices[2][k] = z; - z += step; - ++k; - } - x += step; - z = 0.0f; - } -#if DEBUG_ENABLED - for (i = 0 ; i < MAP_NUM_TOTAL_VERTICES ; ++i) - { - printf ("Vertice %d (%f, %f, %f)\n", - i, map_vertices[0][i], map_vertices[1][i], map_vertices[2][i]); - - } -#endif - /* create indices */ - /* line fan based on i - * i+1 - * | / i + n + 1 - * | / - * |/ - * i --- i + n - */ - - /* close the top of the square */ - k = 0; - for (i = 0 ; i < MAP_NUM_VERTICES -1 ; ++i) - { - map_line_indices[k++] = (i + 1) * MAP_NUM_VERTICES -1; - map_line_indices[k++] = (i + 2) * MAP_NUM_VERTICES -1; - } - /* close the right of the square */ - for (i = 0 ; i < MAP_NUM_VERTICES -1 ; ++i) - { - map_line_indices[k++] = (MAP_NUM_VERTICES - 1) * MAP_NUM_VERTICES + i; - map_line_indices[k++] = (MAP_NUM_VERTICES - 1) * MAP_NUM_VERTICES + i + 1; - } - - for (i = 0 ; i < (MAP_NUM_VERTICES - 1) ; ++i) - { - for (j = 0 ; j < (MAP_NUM_VERTICES - 1) ; ++j) - { - int ref = i * (MAP_NUM_VERTICES) + j; - map_line_indices[k++] = ref; - map_line_indices[k++] = ref + 1; - - map_line_indices[k++] = ref; - map_line_indices[k++] = ref + MAP_NUM_VERTICES; - - map_line_indices[k++] = ref; - map_line_indices[k++] = ref + MAP_NUM_VERTICES + 1; - } - } - -#ifdef DEBUG_ENABLED - for (k = 0 ; k < 2 * MAP_NUM_LINES ; k += 2) - { - int beg, end; - beg = map_line_indices[k]; - end = map_line_indices[k+1]; - printf ("Line %d: %d -> %d (%f, %f, %f) -> (%f, %f, %f)\n", - k / 2, beg, end, - map_vertices[0][beg], map_vertices[1][beg], map_vertices[2][beg], - map_vertices[0][end], map_vertices[1][end], map_vertices[2][end]); - } -#endif -} - -static void generate_heightmap__circle(float* center_x, float* center_y, - float* size, float* displacement) -{ - float sign; - /* random value for element in between [0-1.0] */ - *center_x = (MAP_SIZE * rand()) / (float) RAND_MAX; - *center_y = (MAP_SIZE * rand()) / (float) RAND_MAX; - *size = (MAX_CIRCLE_SIZE * rand()) / (float) RAND_MAX; - sign = (1.0f * rand()) / (float) RAND_MAX; - sign = (sign < DISPLACEMENT_SIGN_LIMIT) ? -1.0f : 1.0f; - *displacement = (sign * (MAX_DISPLACEMENT * rand())) / (float) RAND_MAX; -} - -/* Run the specified number of iterations of the generation process for the - * heightmap - */ -static void update_map(int num_iter) -{ - assert(num_iter > 0); - while(num_iter) - { - /* center of the circle */ - float center_x; - float center_z; - float circle_size; - float disp; - size_t ii; - generate_heightmap__circle(¢er_x, ¢er_z, &circle_size, &disp); - disp = disp / 2.0f; - for (ii = 0u ; ii < MAP_NUM_TOTAL_VERTICES ; ++ii) - { - GLfloat dx = center_x - map_vertices[0][ii]; - GLfloat dz = center_z - map_vertices[2][ii]; - GLfloat pd = (2.0f * (float) sqrt((dx * dx) + (dz * dz))) / circle_size; - if (fabs(pd) <= 1.0f) - { - /* tx,tz is within the circle */ - GLfloat new_height = disp + (float) (cos(pd*3.14f)*disp); - map_vertices[1][ii] += new_height; - } - } - --num_iter; - } -} - -/********************************************************************** - * OpenGL helper functions - *********************************************************************/ - -/* Create VBO, IBO and VAO objects for the heightmap geometry and bind them to - * the specified program object - */ -static void make_mesh(GLuint program) -{ - GLuint attrloc; - - glGenVertexArrays(1, &mesh); - glGenBuffers(4, mesh_vbo); - glBindVertexArray(mesh); - /* Prepare the data for drawing through a buffer inidices */ - glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, mesh_vbo[3]); - glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(GLuint)* MAP_NUM_LINES * 2, map_line_indices, GL_STATIC_DRAW); - - /* Prepare the attributes for rendering */ - attrloc = glGetAttribLocation(program, "x"); - glBindBuffer(GL_ARRAY_BUFFER, mesh_vbo[0]); - glBufferData(GL_ARRAY_BUFFER, sizeof(GLfloat) * MAP_NUM_TOTAL_VERTICES, &map_vertices[0][0], GL_STATIC_DRAW); - glEnableVertexAttribArray(attrloc); - glVertexAttribPointer(attrloc, 1, GL_FLOAT, GL_FALSE, 0, 0); - - attrloc = glGetAttribLocation(program, "z"); - glBindBuffer(GL_ARRAY_BUFFER, mesh_vbo[2]); - glBufferData(GL_ARRAY_BUFFER, sizeof(GLfloat) * MAP_NUM_TOTAL_VERTICES, &map_vertices[2][0], GL_STATIC_DRAW); - glEnableVertexAttribArray(attrloc); - glVertexAttribPointer(attrloc, 1, GL_FLOAT, GL_FALSE, 0, 0); - - attrloc = glGetAttribLocation(program, "y"); - glBindBuffer(GL_ARRAY_BUFFER, mesh_vbo[1]); - glBufferData(GL_ARRAY_BUFFER, sizeof(GLfloat) * MAP_NUM_TOTAL_VERTICES, &map_vertices[1][0], GL_DYNAMIC_DRAW); - glEnableVertexAttribArray(attrloc); - glVertexAttribPointer(attrloc, 1, GL_FLOAT, GL_FALSE, 0, 0); -} - -/* Update VBO vertices from source data - */ -static void update_mesh(void) -{ - glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(GLfloat) * MAP_NUM_TOTAL_VERTICES, &map_vertices[1][0]); -} - -/********************************************************************** - * GLFW callback functions - *********************************************************************/ - -static void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods) -{ - switch(key) - { - case GLFW_KEY_ESCAPE: - /* Exit program on Escape */ - glfwSetWindowShouldClose(window, GLFW_TRUE); - break; - } -} - -static void error_callback(int error, const char* description) -{ - fprintf(stderr, "Error: %s\n", description); -} - -int main(int argc, char** argv) -{ - GLFWwindow* window; - int iter; - double dt; - double last_update_time; - int frame; - float f; - GLint uloc_modelview; - GLint uloc_project; - int width, height; - - GLuint shader_program; - - glfwSetErrorCallback(error_callback); - - if (!glfwInit()) - exit(EXIT_FAILURE); - - glfwWindowHint(GLFW_RESIZABLE, GLFW_FALSE); - glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3); - glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 2); - glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); - glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GLFW_TRUE); - - window = glfwCreateWindow(800, 600, "GLFW OpenGL3 Heightmap demo", NULL, NULL); - if (! window ) - { - glfwTerminate(); - exit(EXIT_FAILURE); - } - - /* Register events callback */ - glfwSetKeyCallback(window, key_callback); - - glfwMakeContextCurrent(window); - gladLoadGL(glfwGetProcAddress); - - /* Prepare opengl resources for rendering */ - shader_program = make_shader_program(vertex_shader_text, fragment_shader_text); - - if (shader_program == 0u) - { - glfwTerminate(); - exit(EXIT_FAILURE); - } - - glUseProgram(shader_program); - uloc_project = glGetUniformLocation(shader_program, "project"); - uloc_modelview = glGetUniformLocation(shader_program, "modelview"); - - /* Compute the projection matrix */ - f = 1.0f / tanf(view_angle / 2.0f); - projection_matrix[0] = f / aspect_ratio; - projection_matrix[5] = f; - projection_matrix[10] = (z_far + z_near)/ (z_near - z_far); - projection_matrix[11] = -1.0f; - projection_matrix[14] = 2.0f * (z_far * z_near) / (z_near - z_far); - glUniformMatrix4fv(uloc_project, 1, GL_FALSE, projection_matrix); - - /* Set the camera position */ - modelview_matrix[12] = -5.0f; - modelview_matrix[13] = -5.0f; - modelview_matrix[14] = -20.0f; - glUniformMatrix4fv(uloc_modelview, 1, GL_FALSE, modelview_matrix); - - /* Create mesh data */ - init_map(); - make_mesh(shader_program); - - /* Create vao + vbo to store the mesh */ - /* Create the vbo to store all the information for the grid and the height */ - - /* setup the scene ready for rendering */ - glfwGetFramebufferSize(window, &width, &height); - glViewport(0, 0, width, height); - glClearColor(0.0f, 0.0f, 0.0f, 0.0f); - - /* main loop */ - frame = 0; - iter = 0; - last_update_time = glfwGetTime(); - - while (!glfwWindowShouldClose(window)) - { - ++frame; - /* render the next frame */ - glClear(GL_COLOR_BUFFER_BIT); - glDrawElements(GL_LINES, 2* MAP_NUM_LINES , GL_UNSIGNED_INT, 0); - - /* display and process events through callbacks */ - glfwSwapBuffers(window); - glfwPollEvents(); - /* Check the frame rate and update the heightmap if needed */ - dt = glfwGetTime(); - if ((dt - last_update_time) > 0.2) - { - /* generate the next iteration of the heightmap */ - if (iter < MAX_ITER) - { - update_map(NUM_ITER_AT_A_TIME); - update_mesh(); - iter += NUM_ITER_AT_A_TIME; - } - last_update_time = dt; - frame = 0; - } - } - - glfwTerminate(); - exit(EXIT_SUCCESS); -} - |