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Diffstat (limited to 'source/lessons/blending/main.cpp')
| -rw-r--r-- | source/lessons/blending/main.cpp | 942 |
1 files changed, 942 insertions, 0 deletions
diff --git a/source/lessons/blending/main.cpp b/source/lessons/blending/main.cpp new file mode 100644 index 0000000..2f07c0e --- /dev/null +++ b/source/lessons/blending/main.cpp @@ -0,0 +1,942 @@ +#include <stdio.h> +#include <SDL2/SDL.h> +#include <glad/glad.h> +#include <assimp/Importer.hpp> +#include <assimp/scene.h> +#include <assimp/postprocess.h> +#include <vector> + +#define STB_IMAGE_IMPLEMENTATION +#include "stb_image.h" + +/* @lookup: +* - I do not understand how floating point numbers work, so I should probably look into that. +* - The normal matrix calculation in the fragment shader for the object affected by light has been mainly copied. +* I have tried to understand the formula, and whilst it made some sense, it is not fully clear to me, and I cannot picture it yet. +* Revisit the derivation for the normal matrix some time in the future. +* - Lookup the derivation of the formula for reflecting a vector about a normal. I am doing that for specular lighting, but the learnopengl tutorial +* just uses a glsl reflect formula, and at the time of writing it is also very late so I am not in the mood or position to look into it at present. +* - One of the things I have observed with specular lights is that the circle/specular highlight follows the camera (me) when I move. I would like to figure +* out a way by which this does not happen and it remains fixed on the object, at the angle at which it hits. All of this will be made complicated by the fact +* that ofcourse everything is actually happening from the cameras' perspective. I would still love to figure this out. +*/ + +typedef uint8_t u8; +typedef uint16_t u16; +typedef uint32_t u32; +typedef uint64_t u64; + +typedef int8_t s8; +typedef int16_t s16; +typedef int32_t s32; +typedef int64_t s64; + +typedef float r32; +typedef double r64; + +typedef u8 b8; + +#include "math.h" + +// =========== Shader Loading ============= + +unsigned int gl_create_vertex_shader(char* vertex_shader_source) +{ + unsigned int vertex_shader = glCreateShader(GL_VERTEX_SHADER); + glShaderSource(vertex_shader, 1, &vertex_shader_source, NULL); + glCompileShader(vertex_shader); + + int success; + char info_log[512]; + glGetShaderiv(vertex_shader, GL_COMPILE_STATUS, &success); + if (!success) + { + glGetShaderInfoLog(vertex_shader, 512, NULL, info_log); + printf("================================\n"); + printf("vertex shader compilation failed:\n%s\n", info_log); + } + + return vertex_shader; +} + +unsigned int gl_create_fragment_shader(char* fragment_shader_source) +{ + unsigned int fragment_shader = glCreateShader(GL_FRAGMENT_SHADER); + glShaderSource(fragment_shader, 1, &fragment_shader_source, NULL); + glCompileShader(fragment_shader); + + int success; + char info_log[512]; + glGetShaderiv(fragment_shader, GL_COMPILE_STATUS, &success); + if (!success) + { + glGetShaderInfoLog(fragment_shader, 512, NULL, info_log); + printf("================================\n"); + printf("fragment shader compilation failed:\n%s\n", info_log); + } + + return fragment_shader; +} + +unsigned int gl_create_shader_program(unsigned int vertex_shader, unsigned int fragment_shader) +{ + unsigned int shader_program = glCreateProgram(); + + glAttachShader(shader_program, vertex_shader); + glAttachShader(shader_program, fragment_shader); + glLinkProgram(shader_program); + + int success; + char info_log[512]; + glGetProgramiv(shader_program, GL_LINK_STATUS, &success); + if (!success) + { + glGetProgramInfoLog(shader_program, 512, NULL, info_log); + printf("================================\n"); + printf("shader program linking failed:\n%s\n", info_log); + } + + glDeleteShader(vertex_shader); + glDeleteShader(fragment_shader); + + return shader_program; +} + +unsigned int gl_shader_program(char* vertex_shader_source, char* fragment_shader_source) +{ + unsigned int vertex_shader = gl_create_vertex_shader(vertex_shader_source); + unsigned int fragment_shader = gl_create_fragment_shader(fragment_shader_source); + unsigned int shader_program = gl_create_shader_program(vertex_shader, fragment_shader); + + return shader_program; +} + +Mat4 camera_create4m(Vec3 camera_pos, Vec3 camera_look, Vec3 camera_up) +{ + // @note: We do this because this allows the camera to have the axis it looks at + // inwards be the +z axis. + // If we did not do this, then the inward axis the camera looks at would be negative. + // I am still learning from learnopengl.com but I imagine that this was done for conveniences' sake. + Vec3 camera_forward_dir = normalize3v(subtract3v(camera_pos, camera_look)); + Vec3 camera_right_dir = normalize3v(cross_multiply3v(camera_up, camera_forward_dir)); + Vec3 camera_up_dir = normalize3v(cross_multiply3v(camera_forward_dir, camera_right_dir)); + + Mat4 res = lookat4m(camera_up_dir, camera_forward_dir, camera_right_dir, camera_pos); + + return res; +} + +Vec3 camera_look_around(r32 angle_pitch, r32 angle_yaw) +{ + Vec3 camera_look = {0.0}; + camera_look.x = cosf(angle_yaw) * cosf(angle_pitch); + camera_look.y = sinf(angle_pitch); + camera_look.z = sinf(angle_yaw) * cosf(angle_pitch); + camera_look = normalize3v(camera_look); + + return camera_look; +} + +s32 gl_load_texture(u32 texture_id, const char* path) +{ + s32 width, height, nrChannels; + unsigned char *data = stbi_load(path, &width, &height, &nrChannels, 0); + if (data) + { + GLenum format; + if (nrChannels == 1) + format = GL_RED; + else if (nrChannels == 3) + format = GL_RGB; + else if (nrChannels == 4) + format = GL_RGBA; + + glBindTexture(GL_TEXTURE_2D, texture_id); + glTexImage2D(GL_TEXTURE_2D, 0, format, width, height, 0, format, GL_UNSIGNED_BYTE, data); + glGenerateMipmap(GL_TEXTURE_2D); + + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT); + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR); + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); + + stbi_image_free(data); + } + else + { + printf("failed to load image texture at path: %s", path); + stbi_image_free(data); + } + + return texture_id; +} + +// =================== Model Loading ======================== +// This section contains a whole host of things: +// 1. classes +// 2. std::vectors +// 3. std::strings +// that I have only used as a glue for I did not know if I had the model loading setup properly. +// @todo: replace these things eventually. For now the goal is to complete learnopengl + +s32 TextureFromFile(const char* filepath, std::string directory) +{ + std::string filename = std::string(filepath); + filename = directory + '/' + filename; + + u32 texid; + glGenTextures(1, &texid); + + s32 width, height, nrChannels; + unsigned char *data = stbi_load(filename.c_str(), &width, &height, &nrChannels, 0); + if (data) + { + GLenum format; + if (nrChannels == 1) + format = GL_RED; + else if (nrChannels == 3) + format = GL_RGB; + else if (nrChannels == 4) + format = GL_RGBA; + + glBindTexture(GL_TEXTURE_2D, texid); + glTexImage2D(GL_TEXTURE_2D, 0, format, width, height, 0, format, GL_UNSIGNED_BYTE, data); + glGenerateMipmap(GL_TEXTURE_2D); + + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT); + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR); + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); + + stbi_image_free(data); + } + else + { + printf("failed to load image texture at path: %s", filepath); + stbi_image_free(data); + } + + return texid; +} + +enum TextureType { TextureDiffuse=0, TextureSpecular }; + +struct Vertex { + Vec3 position; + Vec3 normal; + Vec2 texture; +}; + +struct Texture { + u32 id; + enum TextureType type; + std::string fname; +}; + +class Mesh { + public: + std::vector<Vertex> vertices; + std::vector<u32> indices; + std::vector<Texture> textures; + + u32 vao; + u32 vbo; + u32 ebo; + + Mesh(std::vector<Vertex> vertices, std::vector<u32> indices, std::vector<Texture> textures) + { + this->vertices = vertices; + this->indices = indices; + this->textures = textures; + + // setup mesh shader stuff + glGenVertexArrays(1, &vao); + glGenBuffers(1, &vbo); + glGenBuffers(1, &ebo); + + glBindVertexArray(vao); + + glBindBuffer(GL_ARRAY_BUFFER, vbo); + glBufferData(GL_ARRAY_BUFFER, this->vertices.size() * sizeof(struct Vertex), &(this->vertices[0]), GL_STATIC_DRAW); + + glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo); + glBufferData(GL_ELEMENT_ARRAY_BUFFER, this->indices.size() * sizeof(u32), &(this->indices[0]), GL_STATIC_DRAW); + + // position + glEnableVertexAttribArray(0); + glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)0); + // normal + glEnableVertexAttribArray(1); + glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)offsetof(Vertex, normal)); + // texture + glEnableVertexAttribArray(2); + glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)offsetof(Vertex, texture)); + + glBindVertexArray(0); + } + + void draw(u32 shader_program) + { + glUseProgram(shader_program); + + u32 diffuse_num = 1; + u32 specular_num = 1; + char tex_unit_name[64]; + // set shininess + s32 mat_shine_loc = glGetUniformLocation(shader_program, "material.shininess"); + glUniform1f(mat_shine_loc, 32.0f); + + for (u32 i=0; i<textures.size(); i++) + { + struct Texture curr_tex = textures[i]; + if (curr_tex.type == TextureDiffuse) + { + sprintf(tex_unit_name, "material.diffuse[%i]", diffuse_num); + } + else if (curr_tex.type == TextureSpecular) + { + sprintf(tex_unit_name, "material.diffuse[%i]", specular_num); + } + + glActiveTexture(GL_TEXTURE0 + i); + s32 tex_unit_loc = glGetUniformLocation(shader_program, tex_unit_name); + glUniform1i(tex_unit_loc, i); + glBindTexture(GL_TEXTURE_2D, curr_tex.id); + } + glActiveTexture(GL_TEXTURE0); + + glBindVertexArray(vao); + glDrawElements(GL_TRIANGLES, indices.size(), GL_UNSIGNED_INT, 0); + glBindVertexArray(0); + } +}; + +class Model +{ + public: + Model(std::string path) + { + load_model(path); + } + void draw(u32 shader_program); + private: + std::vector<Texture> loaded_textures; + std::vector<Mesh> meshes; + std::string directory; + + void load_model(std::string path); + void process_node(aiNode *node, const aiScene *scene); + Mesh process_mesh(aiMesh *mesh, const aiScene *scene); + std::vector<Texture> load_material_textures(aiMaterial *mat, aiTextureType type, TextureType type_name); +}; + +void Model::draw(u32 shader_program) +{ + for (int i=0; i < meshes.size(); i++) + { + meshes[i].draw(shader_program); + } +} + +void Model::load_model(std::string path) +{ + Assimp::Importer import; + const aiScene *scene = import.ReadFile(path, aiProcess_Triangulate | aiProcess_FlipUVs); + + if (!scene || scene->mFlags & AI_SCENE_FLAGS_INCOMPLETE || !scene->mRootNode) + { + printf("error loading model :%s\n", import.GetErrorString()); + return; + } + + directory = path.substr(0, path.find_last_of('/')); + process_node(scene->mRootNode, scene); +} + +void Model::process_node(aiNode *node, const aiScene *scene) +{ + for (int i=0; i < node->mNumMeshes; i++) + { + aiMesh *mesh = scene->mMeshes[node->mMeshes[i]]; + meshes.push_back(process_mesh(mesh, scene)); + } + + for (int i=0; i<node->mNumChildren; i++) + { + process_node(node->mChildren[i], scene); + } +} + +Mesh Model::process_mesh(aiMesh *mesh, const aiScene *scene) +{ + std::vector<Vertex> vertices; + std::vector<u32> indices; + std::vector<Texture> textures; + + for (u32 i=0; i < mesh->mNumVertices; i++) + { + Vec3 position; + position.x = mesh->mVertices[i].x; + position.y = mesh->mVertices[i].y; + position.z = mesh->mVertices[i].z; + + Vec3 normal; + normal.x = mesh->mNormals[i].x; + normal.y = mesh->mNormals[i].y; + normal.z = mesh->mNormals[i].z; + + Vec2 texture = {0, 0}; + if (mesh->mTextureCoords[0]) + { + texture.x = mesh->mTextureCoords[0][i].x; + texture.y = mesh->mTextureCoords[0][i].y; + } + + struct Vertex vertex; + vertex.position = position; + vertex.normal = normal; + vertex.texture = texture; + + vertices.push_back(vertex); + } + // process indices + for (u32 i = 0; i < mesh->mNumFaces; i++) + { + aiFace face = mesh->mFaces[i]; + for(u32 j = 0; j < face.mNumIndices; j++) + { + indices.push_back(face.mIndices[j]); + } + } + // process material + if (mesh->mMaterialIndex >= 0) + { + aiMaterial *material = scene->mMaterials[mesh->mMaterialIndex]; + std::vector<Texture> diffuse_maps = load_material_textures(material, aiTextureType_DIFFUSE, TextureDiffuse); + textures.insert(textures.end(), diffuse_maps.begin(), diffuse_maps.end()); + std::vector<Texture> specular_maps = load_material_textures(material, aiTextureType_SPECULAR, TextureSpecular); + textures.insert(textures.end(), specular_maps.begin(), specular_maps.end()); + } + + return Mesh(vertices, indices, textures); +} + +std::vector<Texture> Model::load_material_textures(aiMaterial *mat, aiTextureType type, TextureType tex_type) +{ + std::vector<Texture> textures; + for(u32 i=0; i<mat->GetTextureCount(type); i++) + { + bool load_texture = true; + aiString str; + mat->GetTexture(type, i, &str); + const char* fname = str.C_Str(); + + for (s32 j=0; j<loaded_textures.size(); j++) + { + if (std::strcmp(loaded_textures[j].fname.data(), fname) == 0) + { + load_texture = false; + textures.push_back(loaded_textures[j]); + break; + } + } + if (load_texture) + { + Texture texture; + texture.id = TextureFromFile(fname, directory); + texture.type = tex_type; + texture.fname = std::string(fname); + textures.push_back(texture); + loaded_textures.push_back(texture); + } + } + + return textures; +} + +int main(int argc, char* argv[]) +{ + + // ============ END ============ + int width = 1024; + int height = 768; + + if (SDL_Init(SDL_INIT_VIDEO) != 0) + { + printf("Error initialising SDL2: %s\n", SDL_GetError()); + return 0; + }; + + // set opengl version and profile + SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3); + SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 3); + SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE); + SDL_GL_SetAttribute( SDL_GL_STENCIL_SIZE, 8 ); + + // initialise window with opengl flag + SDL_Window* window = SDL_CreateWindow("SDL Test", + 50, + 50, + width, + height, + SDL_WINDOW_OPENGL); + + SDL_SetRelativeMouseMode(SDL_TRUE); + + // create an opengl context + SDL_GLContext context = SDL_GL_CreateContext(window); + if (!context) + { + printf("OpenGL context creation failed: %s\n", SDL_GetError()); + return -1; + } + + + // load glad + if (!gladLoadGLLoader((GLADloadproc)SDL_GL_GetProcAddress)) { + printf("Failed to initialize Glad\n"); + return 1; + } + + // filesystem playground stuff + size_t read_count; + char* vertex_source = (char*)SDL_LoadFile("./source/shaders/depth_test.vs.glsl", &read_count); + char* fragment_source = (char*)SDL_LoadFile("./source/shaders/depth_test.fs.glsl", &read_count); + char* blend_shader_source = (char*)SDL_LoadFile("./source/shaders/blend_test.fs.glsl", &read_count); + + u32 shader_program = gl_shader_program(vertex_source, fragment_source); + u32 blend_shader_program = gl_shader_program(vertex_source, blend_shader_source); + + printf("Successfully compiled shaders.\n"); + + float cubeVertices[] = { + // positions // texture Coords + -0.5f, -0.5f, -0.5f, 0.0f, 0.0f, + 0.5f, -0.5f, -0.5f, 1.0f, 0.0f, + 0.5f, 0.5f, -0.5f, 1.0f, 1.0f, + 0.5f, 0.5f, -0.5f, 1.0f, 1.0f, + -0.5f, 0.5f, -0.5f, 0.0f, 1.0f, + -0.5f, -0.5f, -0.5f, 0.0f, 0.0f, + + -0.5f, -0.5f, 0.5f, 0.0f, 0.0f, + 0.5f, -0.5f, 0.5f, 1.0f, 0.0f, + 0.5f, 0.5f, 0.5f, 1.0f, 1.0f, + 0.5f, 0.5f, 0.5f, 1.0f, 1.0f, + -0.5f, 0.5f, 0.5f, 0.0f, 1.0f, + -0.5f, -0.5f, 0.5f, 0.0f, 0.0f, + + -0.5f, 0.5f, 0.5f, 1.0f, 0.0f, + -0.5f, 0.5f, -0.5f, 1.0f, 1.0f, + -0.5f, -0.5f, -0.5f, 0.0f, 1.0f, + -0.5f, -0.5f, -0.5f, 0.0f, 1.0f, + -0.5f, -0.5f, 0.5f, 0.0f, 0.0f, + -0.5f, 0.5f, 0.5f, 1.0f, 0.0f, + + 0.5f, 0.5f, 0.5f, 1.0f, 0.0f, + 0.5f, 0.5f, -0.5f, 1.0f, 1.0f, + 0.5f, -0.5f, -0.5f, 0.0f, 1.0f, + 0.5f, -0.5f, -0.5f, 0.0f, 1.0f, + 0.5f, -0.5f, 0.5f, 0.0f, 0.0f, + 0.5f, 0.5f, 0.5f, 1.0f, 0.0f, + + -0.5f, -0.5f, -0.5f, 0.0f, 1.0f, + 0.5f, -0.5f, -0.5f, 1.0f, 1.0f, + 0.5f, -0.5f, 0.5f, 1.0f, 0.0f, + 0.5f, -0.5f, 0.5f, 1.0f, 0.0f, + -0.5f, -0.5f, 0.5f, 0.0f, 0.0f, + -0.5f, -0.5f, -0.5f, 0.0f, 1.0f, + + -0.5f, 0.5f, -0.5f, 0.0f, 1.0f, + 0.5f, 0.5f, -0.5f, 1.0f, 1.0f, + 0.5f, 0.5f, 0.5f, 1.0f, 0.0f, + 0.5f, 0.5f, 0.5f, 1.0f, 0.0f, + -0.5f, 0.5f, 0.5f, 0.0f, 0.0f, + -0.5f, 0.5f, -0.5f, 0.0f, 1.0f + }; + float planeVertices[] = { + // positions // texture Coords (note we set these higher than 1 (together with GL_REPEAT as texture wrapping mode). this will cause the floor texture to repeat) + 5.0f, -0.5f, 5.0f, 2.0f, 0.0f, + -5.0f, -0.5f, 5.0f, 0.0f, 0.0f, + -5.0f, -0.5f, -5.0f, 0.0f, 2.0f, + + 5.0f, -0.5f, 5.0f, 2.0f, 0.0f, + -5.0f, -0.5f, -5.0f, 0.0f, 2.0f, + 5.0f, -0.5f, -5.0f, 2.0f, 2.0f + }; + float quadVertices[] = { + // positions // texture Coords + -0.5f, -0.5f, 0.0f, 0.0f, + 0.5f, -0.5f, 1.0f, 0.0f, + 0.5f, 0.5f, 1.0f, 1.0f, + 0.5f, 0.5f, 1.0f, 1.0f, + -0.5f, 0.5f, 0.0f, 1.0f, + -0.5f, -0.5f, 0.0f, 0.0f, + }; + stbi_set_flip_vertically_on_load(1); + + u32 cube_vao, cube_vbo, plane_vao, plane_vbo, quad_vao, quad_vbo; + + glGenVertexArrays(1, &cube_vao); + glGenBuffers(1, &cube_vbo); + + glBindVertexArray(cube_vao); + glBindBuffer(GL_ARRAY_BUFFER, cube_vbo); + glBufferData(GL_ARRAY_BUFFER, sizeof(cubeVertices), &cubeVertices, GL_STATIC_DRAW); + glEnableVertexAttribArray(0); + glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)0); + glEnableVertexAttribArray(1); + glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)(3*sizeof(float))); + glBindVertexArray(0); + + glGenVertexArrays(1, &plane_vao); + glGenBuffers(1, &plane_vbo); + + glBindVertexArray(plane_vao); + glBindBuffer(GL_ARRAY_BUFFER, plane_vbo); + glBufferData(GL_ARRAY_BUFFER, sizeof(planeVertices), &planeVertices, GL_STATIC_DRAW); + glEnableVertexAttribArray(0); + glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)0); + glEnableVertexAttribArray(1); + glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)(3*sizeof(float))); + glBindVertexArray(0); + + glGenVertexArrays(1, &quad_vao); + glGenBuffers(1, &quad_vbo); + + glBindVertexArray(quad_vao); + glBindBuffer(GL_ARRAY_BUFFER, quad_vbo); + glBufferData(GL_ARRAY_BUFFER, sizeof(quadVertices), &quadVertices, GL_STATIC_DRAW); + glEnableVertexAttribArray(0); + glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(float), (void*)0); + glEnableVertexAttribArray(1); + glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(float), (void*)(2*sizeof(float))); + glBindVertexArray(0); + + u32 cube_tex_id; + glGenTextures(1, &cube_tex_id); + glActiveTexture(GL_TEXTURE0); + gl_load_texture(cube_tex_id, "assets/container.jpg"); + + u32 plane_tex_id; + glGenTextures(1, &plane_tex_id); + glActiveTexture(GL_TEXTURE1); + gl_load_texture(plane_tex_id, "assets/smiling.png"); + + u32 window_tex_id; + glGenTextures(1, &window_tex_id); + glActiveTexture(GL_TEXTURE2); + { + u32 texture_id = window_tex_id; + char *path = "assets/window.png"; + s32 width, height, nrChannels; + unsigned char *data = stbi_load(path, &width, &height, &nrChannels, 0); + if (data) + { + GLenum format; + if (nrChannels == 1) + format = GL_RED; + else if (nrChannels == 3) + format = GL_RGB; + else if (nrChannels == 4) + format = GL_RGBA; + + glBindTexture(GL_TEXTURE_2D, texture_id); + glTexImage2D(GL_TEXTURE_2D, 0, format, width, height, 0, format, GL_UNSIGNED_BYTE, data); + glGenerateMipmap(GL_TEXTURE_2D); + + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR); + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); + + stbi_image_free(data); + } + else + { + printf("failed to load image texture at path: %s", path); + stbi_image_free(data); + } + +} + + // objects + Vec3 model_translations[] = { + Vec3{ 0.5, 0.0, 0.0}, //origin square + Vec3{ -1.0, 0.0, -1.0}, // plane + Vec3{ -1.0, 0.0, -0.5}, // window between squares + Vec3{ 0.0, 0.0, 3.0}, //window infront of origin square + Vec3{ -2.5, 0.0, -0.5}, // square to the left + Vec3{ -1.0, 0.0, -1.5}, // random square behind window between squares + }; + + r32 FOV = 90.0; + r32 time_curr; + r32 time_prev = SDL_GetTicks64() / 100.0; + // camera stuff + Vec3 camera_pos = Vec3{ 0.0, 0.0, 10.0f}; + Vec3 preset_up_dir = Vec3{ 0.0, 1.0, 0.0 }; + + r32 angle_yaw, angle_pitch, angle_roll; + angle_pitch = (r32)To_Radian(0.0f); + angle_yaw = (r32)-To_Radian(90.0f); + + Vec3 camera_look = camera_look_around(angle_pitch, angle_yaw); + + // @todo: remove this, I dont like this and think that this is unnecessary + Vec3 camera_look_increment; + r32 camera_speed = 0.5f; + + Mat4 view = camera_create4m(camera_pos, camera_look, preset_up_dir); + + Mat4 proj = perspective4m((r32)To_Radian(90.0), (r32)width / (r32)height, 0.1f, 100.0f); + // needs this + glUseProgram(shader_program); + uint32_t proj_loc = glGetUniformLocation(shader_program, "Projection"); + glUniformMatrix4fv(proj_loc, 1, GL_TRUE, proj.buffer); + + glUseProgram(blend_shader_program); + proj_loc = glGetUniformLocation(blend_shader_program, "Projection"); + glUniformMatrix4fv(proj_loc, 1, GL_TRUE, proj.buffer); + + glEnable(GL_DEPTH_TEST); + glEnable(GL_BLEND); + glDepthFunc(GL_LESS); + + u8 game_running = true; + + u8 hold_lshift = false; + u8 move_w = false; + u8 move_a = false; + u8 move_s = false; + u8 move_d = false; + + while(game_running) + { + + // frame delta + time_curr = SDL_GetTicks64() / 100.0; + r32 time_delta = time_curr - time_prev; + + r32 camera_speed_adjusted = time_delta * camera_speed; + camera_look_increment = scaler_multiply3v(camera_look, camera_speed_adjusted); + + SDL_Event ev; + while(SDL_PollEvent(&ev)) + { + + // INPUT + switch (ev.type) + { + case (SDL_QUIT): + { + game_running = false; + } break; + case (SDL_KEYDOWN): + { + if (ev.key.keysym.sym == SDLK_LSHIFT) + { + hold_lshift = true; + } + if (ev.key.keysym.sym == SDLK_w) + { + move_w = true; + } + if (ev.key.keysym.sym == SDLK_s) + { + move_s = true; + } + if (ev.key.keysym.sym == SDLK_a) + { + move_a = true; + } + if (ev.key.keysym.sym == SDLK_d) + { + move_d = true; + } + } break; + case (SDL_KEYUP): + { + if (ev.key.keysym.sym == SDLK_LSHIFT) + { + hold_lshift = false; + } + if (ev.key.keysym.sym == SDLK_w) + { + move_w = false; + } + if (ev.key.keysym.sym == SDLK_s) + { + move_s = false; + } + if (ev.key.keysym.sym == SDLK_a) + { + move_a = false; + } + if (ev.key.keysym.sym == SDLK_d) + { + move_d = false; + } + } break; + case (SDL_MOUSEMOTION): + { + SDL_MouseMotionEvent mouse_event = ev.motion; + r32 x_motion = (r32)mouse_event.xrel; + r32 y_motion = (r32)mouse_event.yrel; + if (x_motion != 0.0 || y_motion != 0.0) + { + angle_yaw = angle_yaw + To_Radian(x_motion * 0.1f); + angle_pitch = clampf(angle_pitch + To_Radian(-y_motion * 0.1f), To_Radian(-89.0f), To_Radian(89.0f)); + + camera_look = camera_look_around(angle_pitch, angle_yaw); + } + } break; + default: + { + break; + } + } + } + + // PROCESS + if (move_w) + { + camera_pos = add3v(camera_pos, camera_look_increment); + } + if (move_s) + { + camera_pos = subtract3v(camera_pos, camera_look_increment); + } + if (move_a) + { + Vec3 camera_right = normalize3v(cross_multiply3v(preset_up_dir, camera_look)); + Vec3 camera_right_scaled = scaler_multiply3v(camera_right, camera_speed_adjusted); + camera_pos = add3v(camera_pos, camera_right_scaled); + } + if (move_d) + { + Vec3 camera_right = normalize3v(cross_multiply3v(preset_up_dir, camera_look)); + Vec3 camera_right_scaled = scaler_multiply3v(camera_right, camera_speed_adjusted); + camera_pos = subtract3v(camera_pos, camera_right_scaled); + } + view = camera_create4m(camera_pos, add3v(camera_pos, camera_look), preset_up_dir); + + // object shader program stuff + glUseProgram(shader_program); + uint32_t view_loc = glGetUniformLocation(shader_program, "View"); + glUniformMatrix4fv(view_loc, 1, GL_TRUE, view.buffer); + + glUseProgram(blend_shader_program); + view_loc = glGetUniformLocation(blend_shader_program, "View"); + glUniformMatrix4fv(view_loc, 1, GL_TRUE, view.buffer); + + time_prev = time_curr; + + // OUTPUT + glClearColor(1.0f, 0.6f, .6f, 1.0f); + glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT); + + glDisable(GL_BLEND); + { //plane + glUseProgram(shader_program); + s32 tex_id_loc = glGetUniformLocation(shader_program, "TexId"); + glUniform1i(tex_id_loc, 1); + Vec3 translation_iter = model_translations[1]; + Mat4 model = init_value4m(1.0); + Mat4 model_translation = translation_matrix4m(translation_iter.x, translation_iter.y, translation_iter.z); + model = multiply4m(model_translation, model); + uint32_t model_loc = glGetUniformLocation(shader_program, "Model"); + glUniformMatrix4fv(model_loc, 1, GL_TRUE, model.buffer); + glBindVertexArray(plane_vao); + glDrawArrays(GL_TRIANGLES, 0, 6); + } + + glEnable(GL_BLEND); + glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); + {//origin square + glUseProgram(shader_program); + s32 tex_id_loc = glGetUniformLocation(shader_program, "TexId"); + glUniform1i(tex_id_loc, 0); + Vec3 translation_iter = model_translations[0]; + Mat4 model = init_value4m(1.0); + Mat4 model_translation = translation_matrix4m(translation_iter.x, translation_iter.y, translation_iter.z); + model = multiply4m(model_translation, model); + uint32_t model_loc = glGetUniformLocation(shader_program, "Model"); + glUniformMatrix4fv(model_loc, 1, GL_TRUE, model.buffer); + glBindVertexArray(cube_vao); + glDrawArrays(GL_TRIANGLES, 0, 36); + } + {//square to the left + glUseProgram(shader_program); + s32 tex_id_loc = glGetUniformLocation(shader_program, "TexId"); + glUniform1i(tex_id_loc, 0); + Vec3 translation_iter = model_translations[4]; + Mat4 model = init_value4m(1.0); + Mat4 model_translation = translation_matrix4m(translation_iter.x, translation_iter.y, translation_iter.z); + model = multiply4m(model_translation, model); + uint32_t model_loc = glGetUniformLocation(shader_program, "Model"); + glUniformMatrix4fv(model_loc, 1, GL_TRUE, model.buffer); + glBindVertexArray(cube_vao); + glDrawArrays(GL_TRIANGLES, 0, 36); + } + {//random square behind window between squares + glUseProgram(shader_program); + s32 tex_id_loc = glGetUniformLocation(shader_program, "TexId"); + glUniform1i(tex_id_loc, 0); + Vec3 translation_iter = model_translations[5]; + Mat4 model = init_value4m(1.0); + Mat4 model_translation = translation_matrix4m(translation_iter.x, translation_iter.y, translation_iter.z); + model = multiply4m(model_translation, model); + uint32_t model_loc = glGetUniformLocation(shader_program, "Model"); + glUniformMatrix4fv(model_loc, 1, GL_TRUE, model.buffer); + glBindVertexArray(cube_vao); + glDrawArrays(GL_TRIANGLES, 0, 36); + } + // @note: this is to demonstrate the limitations of blending with the depth buffer. + // Currently, this will show a weird behavior where since we render the transparent object + // closest to the camera first, the second window, further from the player will be discarded by the + // depth buffer and will be invisible. + // This is a limiation of transparent objects with the depth buffer. This does not happen with opaque objects. + // + // The "fix" if we can even call it that, is to render objects in order, furthest first and closest second, in layers. + + {//window infront of origin square + glUseProgram(blend_shader_program); + s32 tex_id_loc = glGetUniformLocation(blend_shader_program, "TexId"); + glUniform1i(tex_id_loc, 2); + Vec3 translation_iter = model_translations[3]; + Mat4 model = init_value4m(1.0); + Mat4 model_translation = translation_matrix4m(translation_iter.x, translation_iter.y, translation_iter.z); + model = multiply4m(model_translation, model); + uint32_t model_loc = glGetUniformLocation(blend_shader_program, "Model"); + glUniformMatrix4fv(model_loc, 1, GL_TRUE, model.buffer); + glBindVertexArray(quad_vao); + glDrawArrays(GL_TRIANGLES, 0, 6); + } + {//window between squares + glUseProgram(blend_shader_program); + s32 tex_id_loc = glGetUniformLocation(blend_shader_program, "TexId"); + glUniform1i(tex_id_loc, 2); + Vec3 translation_iter = model_translations[2]; + Mat4 model = init_value4m(1.0); + Mat4 model_translation = translation_matrix4m(translation_iter.x, translation_iter.y, translation_iter.z); + model = multiply4m(model_translation, model); + uint32_t model_loc = glGetUniformLocation(blend_shader_program, "Model"); + glUniformMatrix4fv(model_loc, 1, GL_TRUE, model.buffer); + glBindVertexArray(quad_vao); + glDrawArrays(GL_TRIANGLES, 0, 6); + } + SDL_GL_SwapWindow(window); + } + + // opengl free calls + //glDeleteVertexArrays(1, &VAO); + //glDeleteBuffers(1, &VBO); + glDeleteProgram(shader_program); + glDeleteProgram(blend_shader_program); + + // sdl free calls + SDL_GL_DeleteContext(context); + SDL_DestroyWindow(window); + SDL_Quit(); + return 0; +} |