2023-11-01 17:09:31 +07:00

257 lines
8.3 KiB
C

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include "libs/cglm/cglm.h"
#include "libs/glad/include/glad/glad.h"
#include <SDL2/SDL.h>
// #include <SDL2/SDL_events.h>
#include "stb_image.h"
// #include <SDL2/SDL_image.h>
// #include <SDL2/SDL_render.h>
#include "lib.h"
//Screen dimension constants
const int SCREEN_WIDTH = 1920;
const int SCREEN_HEIGHT = 768;
int main(void) {
SDL_Window *window = NULL;
if (SDL_Init(SDL_INIT_VIDEO) < 0) {
printf("error initializing SDL: %s\n", SDL_GetError());
return 1;
}
SDL_GL_LoadLibrary(NULL);
// Request an OpenGL 4.5 context (should be core)
SDL_GL_SetAttribute(SDL_GL_ACCELERATED_VISUAL, 1);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 4);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 5);
// Also request a depth buffer
SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);
window = SDL_CreateWindow("Terrain",
SDL_WINDOWPOS_UNDEFINED,
SDL_WINDOWPOS_UNDEFINED,
SCREEN_WIDTH,
SCREEN_HEIGHT,
SDL_WINDOW_OPENGL );
if (window == NULL) {
printf( "Window could not be created! SDL_Error: %s\n", SDL_GetError() );
return 1;
}
SDL_GL_CreateContext(window);
gladLoadGLLoader(SDL_GL_GetProcAddress);
printf("Vendor: %s\n", glGetString(GL_VENDOR));
printf("Renderer: %s\n", glGetString(GL_RENDERER));
printf("Version: %s\n", glGetString(GL_VERSION));
SDL_GL_SetSwapInterval(1);
int res = 16;
int width, height, c;
unsigned char *terrain_img = stbi_load("terrain.png", &width, &height, &c, 0);
int w = width / res;
int h = height / res;
float tw = 100.0f, th = 35.0f;
// int w = 20;
// int h = 20;
int vcount = w * h * 3;
float *terrainVerts = malloc(vcount * sizeof(float));
for (int row = 0; row < h; row++) {
for (int col = 0; col < w; col++) {
int idx = (row * w + col) * 3;
terrainVerts[idx+0] = -tw/2.0f + (float)col/w * tw;
terrainVerts[idx+1] = *(terrain_img + (row * width + col) * c * res) * 0.01f + 1.0f;
terrainVerts[idx+2] = -th/2.0f + (float)row/h * th;
// *(v+1) = y * scale_y + shift_y;
// *(v+1) = -h/2 + row
}
}
stbi_image_free(terrain_img);
// There's 1 less row, so (h-1) * width, then we need to add the extra two
// indices for the degenerate triangles per row, except the first row
// which only has one extra index, since the first index does not need degeneracy
// And then since there are duplicate indices in each row
int icount = (h-1) * (w) * 2 *4;
unsigned int *terrainIndices = malloc(icount * sizeof(unsigned int));
int i = 0;
for (int row = 0; row < h-1; row++) {
for (int col = 0; col < w-1; col++) {
unsigned int topleft = row * w + col;
unsigned int botleft = (row+1) * w + col;
unsigned int botright = (row+1) * w + col+1;
unsigned int topright = row * w + col+1;
terrainIndices[i++] = topleft;
terrainIndices[i++] = botleft;
terrainIndices[i++] = botright;
terrainIndices[i++] = topleft;
terrainIndices[i++] = topright;
terrainIndices[i++] = botright;
}
}
// int i = 0;
// for (int row = 0; row < h-1; row++) {
// if (row != 0) {
// // Duplicate next num
// terrainIndices[i++] = row * w;
// }
// for (int col = 0; col < w; col++) {
// terrainIndices[i++] = (row + 0) * w + col;
// terrainIndices[i++] = (row + 1) * w + col;
// }
// // Duplicate last num
// if (row < h-2) {
// terrainIndices[i] = terrainIndices[i-1];
// i++;
// }
// }
// float terrainVerts[] = {
// float tv[] = {
// 0.f, 0.f, 0.f,
// 1.f, 0.f, 0.f,
// 2.f, 0.f, 0.f,
// 3.f, 0.f, 0.f,
// 0.f, 1.f, 0.f,
// 1.f, 1.f, 0.f,
// 2.f, 1.f, 0.f,
// 3.f, 1.f, 0.f,
// // Second row
// 0.f, 2.f, 0.f,
// 1.f, 2.f, 0.f,
// 2.f, 2.f, 0.f,
// 3.f, 2.f, 0.f,
// 0.f, 3.f, 0.f,
// 1.f, 3.f, 0.f,
// 2.f, 3.f, 0.f,
// 3.f, 3.f, 0.f,
// };
printf("Loaded %d vertices\n", w * h);
unsigned int terrainVAO, terrainVBO, terrainIBO;
glGenVertexArrays(1, &terrainVAO);
glBindVertexArray(terrainVAO);
glGenBuffers(1, &terrainVBO);
glBindBuffer(GL_ARRAY_BUFFER, terrainVBO);
// glBufferData(GL_ARRAY_BUFFER, vcount * sizeof(float), verts, GL_STATIC_DRAW);
glBufferData(GL_ARRAY_BUFFER, vcount * sizeof(float), terrainVerts, GL_STATIC_DRAW);
// position attribute
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
glEnableVertexAttribArray(0);
glGenBuffers(1, &terrainIBO);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, terrainIBO);
int ebosize = icount * sizeof(unsigned int);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, ebosize, terrainIndices, GL_STATIC_DRAW);
// Disable depth test and face culling.
glDisable(GL_DEPTH_TEST);
glDisable(GL_CULL_FACE);
int screen_width,screen_height;
SDL_GetWindowSize(window, &screen_width, &screen_height);
glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
GLuint shaderProgram =
compileShaderProgram("shaders/main.vert", "shaders/main.frag", NULL);
int matrixLocation;
SDL_Event e;
bool quit = false;
Uint64 now = SDL_GetPerformanceCounter();
Uint64 last = 0;
double dt = 0;
bool draw_wireframe = true;
float x = 0.0f, y = 0.0f;
Uint64 frame_count = 0;
float scroll = -10.0f;
while (quit == false) {
frame_count++;
last = now;
now = SDL_GetPerformanceCounter();
dt = (double)((now - last)*1000 / (double)SDL_GetPerformanceFrequency());
(void)dt;
const Uint8* keystates = SDL_GetKeyboardState(NULL);
float speed = 0.5f;
if (keystates[SDL_SCANCODE_W]) {
y += speed;
}
if (keystates[SDL_SCANCODE_S]) {
y -= speed;
}
if (keystates[SDL_SCANCODE_A]) {
x += speed;
}
if (keystates[SDL_SCANCODE_D]) {
x -= speed;
}
while (SDL_PollEvent( &e)) {
if (e.type == SDL_QUIT) {
quit = true;
} else if (e.type == SDL_KEYDOWN) {
char key = e.key.keysym.sym;
if (key == '1') {
draw_wireframe = !draw_wireframe;
}
}
if (e.type == SDL_MOUSEWHEEL) {
if (e.wheel.y > 0) {
scroll -= 2.0f;
} else if(e.wheel.y < 0) {
scroll += 2.0f;
}
}
}
mat4 projection;
glm_mat4_identity(projection);
float aspectRatio = (float)SCREEN_WIDTH / (float)SCREEN_HEIGHT;
glm_perspective(45.0f, aspectRatio, 0.1f, 1000.0f, projection);
mat4 model;
glm_mat4_identity(model);
mat4 view;
glm_mat4_identity(view);
glm_translate(view, (vec3){x, -y, scroll});
// glm_translate(view, (vec3){0.0f, 0.0f, -10.0f});
glm_rotate(model, 45.0f, (vec3){1.0f, 0.0f, 0.0f});
matrixLocation = glGetUniformLocation(shaderProgram, "view");
glUniformMatrix4fv(matrixLocation, 1, GL_FALSE, view[0]);
matrixLocation = glGetUniformLocation(shaderProgram, "projection");
glUniformMatrix4fv(matrixLocation, 1, GL_FALSE, projection[0]);
matrixLocation = glGetUniformLocation(shaderProgram, "model");
glUniformMatrix4fv(matrixLocation, 1, GL_FALSE, model[0]);
glUseProgram(shaderProgram);
glViewport(0, 0, screen_width, screen_height);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
if (draw_wireframe) {
glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
} else {
glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
}
glBindVertexArray(terrainVAO);
glDrawElements(GL_TRIANGLES, icount, GL_UNSIGNED_INT, (void*)0);
SDL_GL_SwapWindow(window);
}
SDL_DestroyWindow( window );
return 0;
}