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-rw-r--r--gl-asylum/main.c980
1 files changed, 980 insertions, 0 deletions
diff --git a/gl-asylum/main.c b/gl-asylum/main.c
new file mode 100644
index 0000000..3320e3e
--- /dev/null
+++ b/gl-asylum/main.c
@@ -0,0 +1,980 @@
+#define GLAD_GL_IMPLEMENTATION
+#include "../common/c_cpp/thirdparty/glad33/glad33.h"
+
+#define SDL_MAIN_USE_CALLBACKS
+#include <SDL3/SDL.h>
+#include <SDL3/SDL_main.h>
+#include <SDL3/SDL_opengl.h>
+
+#include <stddef.h>
+
+#define COUNTOF(arr) (sizeof(arr) / sizeof((arr)[0]))
+#define UNUSED(var) ((void)(var))
+
+// ===========================================================================
+// Data
+// ===========================================================================
+
+typedef struct Vertex3D Vertex3D;
+struct Vertex3D
+{
+ float p[3];
+ float n[3];
+ float t[2];
+ int i;
+};
+
+typedef struct Mesh Mesh;
+struct Mesh
+{
+ GLuint vao;
+ GLuint vbo;
+ GLuint ibo;
+ GLsizei icount;
+};
+
+#define BTN_FORWARD (1 << 0)
+#define BTN_BACKWARD (1 << 1)
+#define BTN_LEFT (1 << 2)
+#define BTN_RIGHT (1 << 3)
+
+#define BTNMASK_MOVE (BTN_FORWARD | BTN_BACKWARD | BTN_LEFT | BTN_RIGHT)
+
+static struct
+{
+ SDL_Window* wnd;
+
+ int depth_dim;
+ GLuint depth_fbo;
+ GLuint depth_tex;
+
+ GLuint world_prog;
+ GLuint world_depth_prog;
+
+ Mesh floor_mesh;
+ Mesh box_mesh;
+
+ GLuint floor_diffuse_tex;
+
+ // Camera
+ float cam_pos[3]; // x, y, z
+ float cam_ang[2]; // yaw, pitch
+ float cam_fov; // degrees
+
+ // Controls
+ unsigned int btns;
+
+ // Time
+ float etime;
+ float gtime;
+ float dtime;
+
+ // Global settings
+ float eye_height;
+ float fog_start_radius;
+ float fog_end_radius;
+ float fog_color[3];
+} G = { 0 };
+
+// ===========================================================================
+// Geometry
+// ===========================================================================
+
+static float lerp(float a, float b, float t) {
+ return a + (b - a) * t;
+}
+
+static inline unsigned int coord_hash(int x, int y)
+{
+ unsigned int xx = (unsigned int)x;
+ unsigned int yy = (unsigned int)y;
+ unsigned int h = xx * 374761393u + yy * 668265263u;
+ h = (h ^ (h >> 13)) * 1274126177u;
+ return h ^ (h >> 16);
+}
+
+// Return float in [0,1)
+static inline float coord_hashf(int x, int y)
+{
+ return (coord_hash(x, y) & 0xFFFFFF) / 16777216.0f;
+}
+
+
+#if 0
+static float degrees(float radians)
+{
+ return radians * 180.0f / SDL_PI_F;
+}
+#endif
+
+static float radians(float degrees)
+{
+ return degrees * SDL_PI_F / 180.0f;
+}
+
+static float lensqv3(const float v[3])
+{
+ return v[0] * v[0] + v[1] * v[1] + v[2] * v[2];
+}
+
+static float lenv3(const float v[3])
+{
+ return SDL_sqrtf(lensqv3(v));
+}
+
+static void copyv3(float dst[3], const float src[3])
+{
+ dst[0] = src[0];
+ dst[1] = src[1];
+ dst[2] = src[2];
+}
+
+static void normv3(float dst[3], const float v[3])
+{
+ float len = lenv3(v);
+ if (len == 0) { len = 1.0f; }
+ dst[0] = v[0] / len;
+ dst[1] = v[1] / len;
+ dst[2] = v[2] / len;
+}
+
+static void addv3(float dst[3], const float left[3], const float right[3])
+{
+ dst[0] = left[0] + right[0];
+ dst[1] = left[1] + right[1];
+ dst[2] = left[2] + right[2];
+}
+
+static void subv3(float dst[3], const float left[3], const float right[3])
+{
+ dst[0] = left[0] - right[0];
+ dst[1] = left[1] - right[1];
+ dst[2] = left[2] - right[2];
+}
+
+static void mulv3(float dst[3], const float left[3], const float right[3])
+{
+ dst[0] = left[0] * right[0];
+ dst[1] = left[1] * right[1];
+ dst[2] = left[2] * right[2];
+}
+
+#if 0
+static void negate3(float dst[3], const float src[3])
+{
+ dst[0] = -src[0];
+ dst[1] = -src[1];
+ dst[2] = -src[2];
+}
+#endif
+
+static void crossv3(float dst[3], const float left[3], const float right[3])
+{
+ const float r[3] = {
+ left[1] * right[2] - left[2] * right[1],
+ left[2] * right[0] - left[0] * right[2],
+ left[0] * right[1] - left[1] * right[0],
+ };
+ copyv3(dst, r);
+}
+
+static float dotv3(const float left[3], const float right[3])
+{
+ return left[0] * right[0] + left[1] * right[1] + left[2] * right[2];
+}
+
+static void forward3(float dir[3], float yaw_deg, float pitch_deg)
+{
+ const float yaw = radians(yaw_deg);
+ const float pitch = radians(pitch_deg);
+ // <0, 0> is towards <0, 0, -1>
+ dir[0] = SDL_sinf(yaw) * SDL_cosf(pitch);
+ dir[1] = SDL_sinf(pitch);
+ dir[2] = -SDL_cosf(yaw) * SDL_cosf(pitch);
+}
+
+static void rotatev3(float dst[3], float inp[3], float around[3], float ang_rad)
+{
+ float axis[3]; copyv3(axis, around);
+ if (lensqv3(axis) < 1e-12f) { copyv3(dst, inp); return; }
+ normv3(axis, axis);
+
+ float c = SDL_cosf(ang_rad);
+ float s = SDL_sinf(ang_rad);
+
+ // (axis × v)
+ float axv[3]; crossv3(axv, axis, inp);
+
+ // (axis · v)
+ float ad = dotv3(axis, inp);
+
+ // Rodrigues' formula:
+ dst[0] = inp[0]*c + axv[0]*s + axis[0]*ad*(1.0f - c);
+ dst[1] = inp[1]*c + axv[1]*s + axis[1]*ad*(1.0f - c);
+ dst[2] = inp[2]*c + axv[2]*s + axis[2]*ad*(1.0f - c);
+}
+
+static void zero4(float m[16])
+{
+ m[ 0] = 0.0f; m[ 1] = 0.0f; m[ 2] = 0.0f; m[ 3] = 0.0f;
+ m[ 4] = 0.0f; m[ 5] = 0.0f; m[ 6] = 0.0f; m[ 7] = 0.0f;
+ m[ 8] = 0.0f; m[ 9] = 0.0f; m[10] = 0.0f; m[11] = 0.0f;
+ m[12] = 0.0f; m[13] = 0.0f; m[14] = 0.0f; m[15] = 0.0f;
+}
+
+static void identity4(float m[16])
+{
+ m[ 0] = 1.0f; m[ 1] = 0.0f; m[ 2] = 0.0f; m[ 3] = 0.0f;
+ m[ 4] = 0.0f; m[ 5] = 1.0f; m[ 6] = 0.0f; m[ 7] = 0.0f;
+ m[ 8] = 0.0f; m[ 9] = 0.0f; m[10] = 1.0f; m[11] = 0.0f;
+ m[12] = 0.0f; m[13] = 0.0f; m[14] = 0.0f; m[15] = 1.0f;
+}
+
+static void copy4(float dst[16], const float src[16])
+{
+ for (int i = 0; i < 16; ++i) {
+ dst[i] = src[i];
+ }
+}
+
+static void mul4(float m[16], const float left[16], const float right[16])
+{
+ float r[16];
+ for (int col = 0; col < 4; ++col) {
+ for (int row = 0; row < 4; ++row) {
+ r[col * 4 + row] =
+ left[0 * 4 + row] * right[col * 4 + 0] +
+ left[1 * 4 + row] * right[col * 4 + 1] +
+ left[2 * 4 + row] * right[col * 4 + 2] +
+ left[3 * 4 + row] * right[col * 4 + 3];
+ }
+ }
+ copy4(m, r);
+}
+
+static void perspective4(float m[16], float fov_deg, float aspect,
+ float z_near, float z_far)
+{
+ const float fov_cot = 1.0f / SDL_tanf(radians(fov_deg) / 2.0f);
+
+ zero4(m);
+
+ m[0*4+0] = fov_cot / aspect;
+ m[1*4+1] = fov_cot;
+ m[2*4+3] = -1.0f;
+
+ m[2*4+2] = (z_far + z_near) / (z_near - z_far);
+ m[3*4+2] = (2.0f * z_near * z_far) / (z_near - z_far);
+}
+
+static void orthographic4(float m[16], float left, float right, float bottom, float top,
+ float z_near, float z_far)
+{
+ const float rl = right - left;
+ const float tb = top - bottom;
+ const float fn = z_far - z_near;
+
+ zero4(m);
+ m[0*4+0] = 2.0f / rl;
+ m[1*4+1] = 2.0f / tb;
+ m[2*4+2] = -2.0f / fn;
+ m[3*4+3] = 1.0f;
+
+ m[3*4+0] = -(right + left) / rl;
+ m[3*4+1] = -(top + bottom) / tb;
+ m[3*4+2] = -(z_far + z_near) / fn;
+}
+
+static void look4(float m[16], const float eye[3], const float at[3], const float up[3])
+{
+ float f[3];
+ subv3(f, at, eye);
+ normv3(f, f);
+
+ float s[3];
+ crossv3(s, f, up);
+ normv3(s, s);
+
+ float u[3];
+ crossv3(u, s, f);
+
+ float t[3] = {
+ -dotv3(s, eye),
+ -dotv3(u, eye),
+ dotv3(f, eye),
+ };
+
+ m[ 0] = s[0]; m[ 1] = u[0]; m[ 2] = -f[0]; m[ 3] = 0.0f;
+ m[ 4] = s[1]; m[ 5] = u[1]; m[ 6] = -f[1]; m[ 7] = 0.0f;
+ m[ 8] = s[2]; m[ 9] = u[2]; m[10] = -f[2]; m[11] = 0.0f;
+ m[12] = t[0]; m[13] = t[1]; m[14] = t[2]; m[15] = 1.0f;
+}
+
+static void translate4(float m[16], const float v[3])
+{
+ identity4(m);
+ m[3*4+0] = v[0];
+ m[3*4+1] = v[1];
+ m[3*4+2] = v[2];
+}
+
+// ===========================================================================
+// OpenGL helpers
+// ===========================================================================
+
+// Helper: Report errors via glGetError() after every OpenGL function call.
+// macOS does not support glDebugMessageCallback
+static void gl_check(GLenum error, const char* expr, int line)
+{
+ if (error != GL_NO_ERROR) {
+ const char* error_string;
+ switch (error) {
+#define BIND_ERROR(name) case name: { error_string = #name; }; break;
+ BIND_ERROR(GL_INVALID_ENUM);
+ BIND_ERROR(GL_INVALID_VALUE);
+ BIND_ERROR(GL_INVALID_OPERATION);
+ BIND_ERROR(GL_INVALID_FRAMEBUFFER_OPERATION);
+ BIND_ERROR(GL_OUT_OF_MEMORY);
+#undef BIND_ERROR
+ default: SDL_assert(0 && "Invalid GL_ERROR enum");
+ }
+ SDL_Log("[Line #%d] %s caused %s\n", line, expr, error_string);
+ }
+}
+#define GLCHECK(expr) expr; gl_check(glGetError(), #expr, __LINE__);
+
+static void create_3d_mesh(Mesh* m, const Vertex3D* v, size_t vcount,
+ const Uint16* i, size_t icount)
+{
+ const size_t vsize = sizeof(*v) * vcount;
+ const size_t isize = sizeof(*i) * icount;
+
+ GLCHECK(glGenVertexArrays(1, &m->vao));
+ GLCHECK(glBindVertexArray(m->vao));
+
+ GLCHECK(glGenBuffers(1, &m->vbo))
+ GLCHECK(glBindBuffer(GL_ARRAY_BUFFER, m->vbo));
+ GLCHECK(glBufferData(GL_ARRAY_BUFFER, vsize, v, GL_STATIC_DRAW));
+
+ GLCHECK(glGenBuffers(1, &m->ibo))
+ GLCHECK(glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m->ibo));
+ GLCHECK(glBufferData(GL_ELEMENT_ARRAY_BUFFER, isize, i, GL_STATIC_DRAW));
+
+ GLCHECK(glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex3D),
+ (void*)offsetof(Vertex3D, p)))
+ GLCHECK(glEnableVertexAttribArray(0));
+ GLCHECK(glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex3D),
+ (void*)offsetof(Vertex3D, n)))
+ GLCHECK(glEnableVertexAttribArray(1));
+ GLCHECK(glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex3D),
+ (void*)offsetof(Vertex3D, t)))
+ GLCHECK(glEnableVertexAttribArray(2));
+ GLCHECK(glVertexAttribIPointer(3, 1, GL_INT, sizeof(Vertex3D),
+ (void*)offsetof(Vertex3D, i)))
+ GLCHECK(glEnableVertexAttribArray(3));
+
+ m->icount = icount;
+}
+
+static GLuint create_texture(int width, int height, void* bmp_rgb)
+{
+ GLuint tex;
+ GLCHECK(glGenTextures(1, &tex));
+
+ GLCHECK(glBindTexture(GL_TEXTURE_2D, tex));
+ GLCHECK(glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB,
+ GL_UNSIGNED_BYTE, bmp_rgb));
+ GLCHECK(glGenerateMipmap(GL_TEXTURE_2D));
+
+ return tex;
+}
+
+static GLuint create_glshader(const char* path, GLenum type)
+{
+ GLuint shader = GLCHECK(glCreateShader(type));
+
+ const char* src = SDL_LoadFile(path, NULL);
+ if (!src) {
+ SDL_Log("Failed to load shader %s: %s\n", path, SDL_GetError());
+ SDL_assert(0);
+ }
+ GLCHECK(glShaderSource(shader, 1, &src, NULL));
+
+ GLCHECK(glCompileShader(shader));
+
+ GLint status;
+ GLCHECK(glGetShaderiv(shader, GL_COMPILE_STATUS, &status));
+ if (status != GL_TRUE) {
+ char error[1024] = { 0 };
+ GLCHECK(glGetShaderInfoLog(shader, sizeof(error), NULL, error));
+ SDL_Log("Error compiling %s: %s\n", path, error);
+ SDL_assert(0);
+ }
+
+ SDL_free((void*)src);
+ return shader;
+}
+
+static GLuint create_glprog(const char* vs_path, const char* fs_path)
+{
+ GLuint prog = GLCHECK(glCreateProgram());
+ GLCHECK(glAttachShader(prog, create_glshader(vs_path, GL_VERTEX_SHADER)));
+ GLCHECK(glAttachShader(prog, create_glshader(fs_path, GL_FRAGMENT_SHADER)));
+ GLCHECK(glLinkProgram(prog));
+
+ GLint status;
+ GLCHECK(glGetProgramiv(prog, GL_LINK_STATUS, &status));
+ if (status != GL_TRUE) {
+ char error[1024] = { 0 };
+ GLCHECK(glGetProgramInfoLog(prog, sizeof(error), NULL, error));
+ SDL_Log("Error linking program: %s\n", error);
+ SDL_assert(0);
+ }
+
+ SDL_Log("Compiled OpenGL program [%s, %s]\n", vs_path, fs_path);
+
+ return prog;
+}
+
+static void set_gluniform_m4(GLuint shader, const char* name, float m[16])
+{
+ GLint p = GLCHECK(glGetUniformLocation(shader, name));
+ SDL_assert(p >= 0 && "incorrect uniform name");
+ GLCHECK(glUniformMatrix4fv(p, 1, GL_FALSE, m));
+}
+
+static void set_gluniform_3f(GLuint shader, const char* name, float v[3])
+{
+ GLint p = GLCHECK(glGetUniformLocation(shader, name));
+ SDL_assert(p >= 0 && "incorrect uniform name");
+ GLCHECK(glUniform3fv(p, 1, v));
+}
+
+static void set_gluniform_4f(GLuint shader, const char* name, float v[4])
+{
+ GLint p = GLCHECK(glGetUniformLocation(shader, name));
+ SDL_assert(p >= 0 && "incorrect uniform name");
+ GLCHECK(glUniform4fv(p, 1, v));
+}
+
+static void set_gluniform_1f(GLuint shader, const char* name, GLfloat f)
+{
+ GLint p = GLCHECK(glGetUniformLocation(shader, name));
+ SDL_assert(p >= 0 && "incorrect uniform name");
+ GLCHECK(glUniform1f(p, f));
+}
+
+static void set_gluniform_1i(GLuint shader, const char* name, GLint i)
+{
+ GLint p = GLCHECK(glGetUniformLocation(shader, name));
+ SDL_assert(p >= 0 && "incorrect uniform name");
+ GLCHECK(glUniform1i(p, i));
+}
+
+// ===========================================================================
+// World generation
+// ===========================================================================
+
+static int cube(int x, int z)
+{
+ int y = 0;
+ if (coord_hashf(x, z) <= 0.1f) {
+ y = coord_hashf(z, x) * 10 + 2;
+ }
+ return y;
+}
+
+// ===========================================================================
+// Rendering
+// ===========================================================================
+
+static void tile_diffusion(GLuint shader, int x, int z)
+{
+ const bool n = cube(x+0, z-1) > 0;
+ const bool ne = cube(x+1, z-1) > 0;
+ const bool e = cube(x+1, z+0) > 0;
+ const bool se = cube(x+1, z+1) > 0;
+ const bool s = cube(x+0, z+1) > 0;
+ const bool sw = cube(x-1, z+1) > 0;
+ const bool w = cube(x-1, z+0) > 0;
+ const bool nw = cube(x-1, z-1) > 0;
+
+ float d[4] = {
+ (w || nw || n) ? 1.0f : 0.0f,
+ (n || ne || e) ? 1.0f : 0.0f,
+ (e || se || s) ? 1.0f : 0.0f,
+ (s || sw || w) ? 1.0f : 0.0f,
+ };
+
+ set_gluniform_4f(shader, "u_diffusion", d);
+}
+
+static void cube_diffusion(GLuint shader, int x, int y, int z)
+{
+ // @@ not done, using a horrible hack in fragment shader
+ UNUSED(x); UNUSED(y); UNUSED(z);
+ // @@
+ float d[4] = { 0.0f, 0.0f,0.0f, 0.0f };
+ set_gluniform_4f(shader, "u_diffusion", d);
+}
+
+static void render_scene(GLuint shader, float view[16], bool depth_only)
+{
+ set_gluniform_m4(shader, "u_view", view);
+
+ // Tiles
+ {
+ GLCHECK(glBindVertexArray(G.floor_mesh.vao));
+
+ if (!depth_only) {
+ GLCHECK(glActiveTexture(GL_TEXTURE0));
+ GLCHECK(glBindTexture(GL_TEXTURE_2D, G.floor_diffuse_tex));
+ set_gluniform_1i(shader, "u_diffuse", 0);
+ }
+
+ float model[16];
+ const int r = (int)G.fog_end_radius + 1;
+ const int cx = (int)G.cam_pos[0];
+ const int cz = (int)G.cam_pos[2];
+ for (int x = cx - r; x <= cx + r; ++x) {
+ for (int z = cz - r; z <= cz + r; ++z) {
+ const float t[3] = { x, 0.0f, z };
+
+ float d[3]; subv3(d, t, G.cam_pos);
+ if (lenv3(d) > G.fog_end_radius) {
+ continue;
+ }
+
+ if (!depth_only) {
+ tile_diffusion(shader, x, z);
+ }
+
+ translate4(model, t);
+ set_gluniform_m4(shader, "u_model", model);
+ GLCHECK(glDrawElements(GL_TRIANGLES, G.floor_mesh.icount, GL_UNSIGNED_SHORT, 0));
+ }
+ }
+ }
+
+ // Cubes
+ {
+ GLCHECK(glBindVertexArray(G.box_mesh.vao));
+
+ if (!depth_only) {
+ GLCHECK(glActiveTexture(GL_TEXTURE0));
+ GLCHECK(glBindTexture(GL_TEXTURE_2D, G.floor_diffuse_tex));
+ set_gluniform_1i(shader, "u_diffuse", 0);
+ }
+
+ float model[16];
+ const int r = (int)G.fog_end_radius + 5;
+ const int cx = (int)G.cam_pos[0];
+ const int cz = (int)G.cam_pos[2];
+ for (int x = cx - r; x <= cx + r; ++x) {
+ for (int z = cz - r; z <= cz + r; ++z) {
+ float t[3] = { x, 0.5f, z };
+
+ const int height = cube(x, z);
+ for (int y = 0; y < height; ++y) {
+ if (!depth_only) {
+ cube_diffusion(shader, x, y, z);
+ }
+ translate4(model, t);
+ set_gluniform_m4(shader, "u_model", model);
+ GLCHECK(glDrawElements(GL_TRIANGLES, G.box_mesh.icount,GL_UNSIGNED_SHORT, 0));
+ t[1] += 1.0f;
+ }
+ }
+ }
+ }
+}
+
+// ===========================================================================
+// SDL callbacks
+// ===========================================================================
+
+SDL_AppResult SDL_AppInit(void** appstate, int argc, char** argv)
+{
+ UNUSED(appstate);
+ UNUSED(argc);
+ UNUSED(argv);
+
+ if (!SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_EVENTS)) {
+ SDL_Log("Failed to initialize SDL: %s\n", SDL_GetError());
+ return SDL_APP_FAILURE;
+ }
+
+ 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_MULTISAMPLEBUFFERS, 1);
+ SDL_GL_SetAttribute(SDL_GL_MULTISAMPLESAMPLES, 4);
+
+ G.wnd = SDL_CreateWindow("demogame", 1024, 768, SDL_WINDOW_HIDDEN |
+ SDL_WINDOW_OPENGL | SDL_WINDOW_HIGH_PIXEL_DENSITY);
+ if (!G.wnd) {
+ SDL_Log("Failed to create game window: %s\n", SDL_GetError());
+ return SDL_APP_FAILURE;
+ }
+
+ if (!SDL_GL_CreateContext(G.wnd)) {
+ SDL_Log("Failed to create OpenGL context: %s\n", SDL_GetError());
+ return SDL_APP_FAILURE;
+ }
+ SDL_GL_SetSwapInterval(1);
+
+ if (!gladLoadGL(SDL_GL_GetProcAddress)) {
+ SDL_Log("gladLoadGL failed\n");
+ return SDL_APP_FAILURE;
+ }
+
+ // Depth map framebuffer
+ G.depth_dim = 8192;
+ GLCHECK(glGenTextures(1, &G.depth_tex));
+ GLCHECK(glBindTexture(GL_TEXTURE_2D, G.depth_tex));
+ GLCHECK(glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, G.depth_dim, G.depth_dim, 0,
+ GL_DEPTH_COMPONENT, GL_FLOAT, NULL));
+ GLCHECK(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST));
+ GLCHECK(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST));
+ GLCHECK(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER));
+ GLCHECK(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER));
+
+ GLCHECK(glGenFramebuffers(1, &G.depth_fbo));
+ GLCHECK(glBindFramebuffer(GL_FRAMEBUFFER, G.depth_fbo));
+ GLCHECK(glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D,
+ G.depth_tex, 0));
+ GLCHECK(glDrawBuffer(GL_NONE));
+ GLCHECK(glReadBuffer(GL_NONE));
+ GLCHECK(glBindFramebuffer(GL_FRAMEBUFFER, 0));
+
+ // Floor mesh: Unit plane along <X, Z>
+ {
+ const Vertex3D v[] = {
+ { { -0.5f, 0.0f, -0.5f }, { 0.0f, 1.0f, 0.0f }, { 0.0f, 1.0f, }, 0, },
+ { { 0.5f, 0.0f, -0.5f }, { 0.0f, 1.0f, 0.0f }, { 1.0f, 1.0f, }, 1, },
+ { { 0.5f, 0.0f, 0.5f }, { 0.0f, 1.0f, 0.0f }, { 1.0f, 0.0f, }, 2, },
+ { { -0.5f, 0.0f, 0.5f }, { 0.0f, 1.0f, 0.0f }, { 0.0f, 0.0f, }, 3, },
+ };
+ const Uint16 i[] = {
+ 0, 1, 2,
+ 0, 2, 3,
+ };
+ create_3d_mesh(&G.floor_mesh, v, COUNTOF(v), i, COUNTOF(i));
+ }
+
+ // Box mesh: Cube with no bottom face
+ {
+ const Vertex3D v[] = {
+ // +z
+ { { -0.5f, 0.5f, 0.5f }, { 0.0f, 0.0f, 1.0f }, { 0.0f, 1.0f, }, 7 },
+ { { 0.5f, 0.5f, 0.5f }, { 0.0f, 0.0f, 1.0f }, { 1.0f, 1.0f, }, 6 },
+ { { 0.5f, -0.5f, 0.5f }, { 0.0f, 0.0f, 1.0f }, { 1.0f, 0.0f, }, 2 },
+ { { -0.5f, -0.5f, 0.5f }, { 0.0f, 0.0f, 1.0f }, { 0.0f, 0.0f, }, 3 },
+ // +x
+ { { 0.5f, 0.5f, 0.5f }, { 1.0f, 0.0f, 0.0f }, { 0.0f, 1.0f, }, 6 },
+ { { 0.5f, 0.5f, -0.5f }, { 1.0f, 0.0f, 0.0f }, { 1.0f, 1.0f, }, 5 },
+ { { 0.5f, -0.5f, -0.5f }, { 1.0f, 0.0f, 0.0f }, { 1.0f, 0.0f, }, 1 },
+ { { 0.5f, -0.5f, 0.5f }, { 1.0f, 0.0f, 0.0f }, { 0.0f, 0.0f, }, 2 },
+ // -z
+ { { 0.5f, 0.5f, -0.5f }, { 0.0f, 0.0f, -1.0f }, { 0.0f, 1.0f, }, 5 },
+ { { -0.5f, 0.5f, -0.5f }, { 0.0f, 0.0f, -1.0f }, { 1.0f, 1.0f, }, 4 },
+ { { -0.5f, -0.5f, -0.5f }, { 0.0f, 0.0f, -1.0f }, { 1.0f, 0.0f, }, 0 },
+ { { 0.5f, -0.5f, -0.5f }, { 0.0f, 0.0f, -1.0f }, { 0.0f, 0.0f, }, 1 },
+ // -x
+ { { -0.5f, 0.5f, -0.5f }, { -1.0f, 0.0f, 0.0f }, { 0.0f, 1.0f, }, 4 },
+ { { -0.5f, 0.5f, 0.5f }, { -1.0f, 0.0f, 0.0f }, { 1.0f, 1.0f, }, 7 },
+ { { -0.5f, -0.5f, 0.5f }, { -1.0f, 0.0f, 0.0f }, { 1.0f, 0.0f, }, 3 },
+ { { -0.5f, -0.5f, -0.5f }, { -1.0f, 0.0f, 0.0f }, { 0.0f, 0.0f, }, 0 },
+ // +y
+ { { -0.5f, 0.5f, -0.5f }, { 0.0f, 1.0f, 0.0f }, { 0.0f, 1.0f, }, 4 },
+ { { 0.5f, 0.5f, -0.5f }, { 0.0f, 1.0f, 0.0f }, { 1.0f, 1.0f, }, 5 },
+ { { 0.5f, 0.5f, 0.5f }, { 0.0f, 1.0f, 0.0f }, { 1.0f, 0.0f, }, 6 },
+ { { -0.5f, 0.5f, 0.5f }, { 0.0f, 1.0f, 0.0f }, { 0.0f, 0.0f, }, 7 },
+ };
+ const Uint16 i[] = {
+ 0, 1, 2,
+ 0, 2, 3,
+ 4, 5, 6,
+ 4, 6, 7,
+ 8, 9, 10,
+ 8, 10, 11,
+ 12, 13, 14,
+ 12, 14, 15,
+ 16, 17, 18,
+ 16, 18, 19,
+ };
+ create_3d_mesh(&G.box_mesh, v, COUNTOF(v), i, COUNTOF(i));
+ }
+
+ // Floor texture
+ {
+ const int dim = 512;
+ unsigned char* bmp = SDL_calloc(dim * dim, 3); SDL_assert(bmp);
+
+ const int r = 4;
+ for (int y = 0; y < dim; ++y) {
+ for (int x = 0; x < dim; ++x) {
+ const int dt = y;
+ const int db = dim - y - 1;
+ const int dl = x;
+ const int dr = dim - x - 1;
+
+ int d = dt;
+ if (db < d) { d = db; }
+ if (dl < d) { d = dl; }
+ if (dr < d) { d = dr; }
+
+ unsigned char bg = 0xEF;
+ int block = 32;
+ if (((x / block) + (y / block)) % 2 == 0 && x > block && y > block
+ && x < dim - block && y < dim - block) {
+ bg = 0xDF;
+ }
+ unsigned char val = (d >= r) ? bg : 0x7F;
+ unsigned char* p = &bmp[(dim * 3) * y + x * 3];
+ p[0] = val;
+ p[1] = val;
+ p[2] = val;
+ }
+ }
+
+ G.floor_diffuse_tex = create_texture(dim, dim, bmp);
+
+ SDL_free(bmp);
+ }
+
+ G.world_prog = create_glprog("world_vs.glsl", "world_fs.glsl");
+ G.world_depth_prog = create_glprog("world_vs.glsl", "world_depth_fs.glsl");
+
+ GLCHECK(glEnable(GL_MULTISAMPLE));
+ GLCHECK(glEnable(GL_DEPTH_TEST));
+ GLCHECK(glEnable(GL_CULL_FACE));
+ GLCHECK(glCullFace(GL_FRONT));
+
+ G.cam_ang[0] = 0.0f;
+ G.cam_ang[1] = 0.0f;
+ G.cam_fov = 90.0f;
+ G.eye_height = 1.5f;
+ G.fog_start_radius = 5.0f;
+ G.fog_end_radius = 15.0f;
+ G.fog_color[0] = G.fog_color[1] = G.fog_color[2] = 0.3f;
+
+ // @@
+ G.cam_pos[2] = 1.5f;
+
+ SDL_ShowWindow(G.wnd);
+
+ return SDL_APP_CONTINUE;
+}
+
+SDL_AppResult SDL_AppIterate(void* appstate)
+{
+ UNUSED(appstate);
+
+ int vp_w;
+ int vp_h;
+ SDL_GetWindowSizeInPixels(G.wnd, &vp_w, &vp_h);
+
+ // ===== Simulate =====
+
+ // Advance time
+ const float now = SDL_GetTicks() / 1e3f;
+ G.dtime = now - G.etime;
+ G.etime = now;
+ G.gtime += G.dtime;
+
+ // Clamp player eye angles
+ G.cam_ang[0] = SDL_fmodf(G.cam_ang[0], 360.0f);
+ if (G.cam_ang[1] > 89.0f) { G.cam_ang[1] = 89.0f; }
+ if (G.cam_ang[1] < -89.0f) { G.cam_ang[1] = -89.0f; }
+
+ // Player movement
+ if (G.btns & BTNMASK_MOVE) {
+ float movedir_f[3]; forward3(movedir_f, G.cam_ang[0], G.cam_ang[1]);
+ movedir_f[1] = 0.0f;
+ normv3(movedir_f, movedir_f);
+
+ float up[3] = { 0.0f, 1.0f, 0.0f };
+ float movedir_r[3]; crossv3(movedir_r, movedir_f, up);
+
+ float move[3] = { 0 };
+ if (G.btns & BTN_FORWARD) { addv3(move, move, movedir_f); }
+ if (G.btns & BTN_BACKWARD) { subv3(move, move, movedir_f); }
+ if (G.btns & BTN_LEFT) { subv3(move, move, movedir_r); }
+ if (G.btns & BTN_RIGHT) { addv3(move, move, movedir_r); }
+ normv3(move, move);
+
+ float speed = 4.0f * G.dtime;
+ float scale[3] = { speed, speed, speed };
+ mulv3(move, move, scale);
+
+ addv3(G.cam_pos, G.cam_pos, move);
+ }
+
+ // Collisions
+ for (int i = 0; i < 8; ++i) {
+ const int xoff[] = { 0, 1, 1, 1, 0, -1, -1, -1 };
+ const int zoff[] = { -1, -1, 0, 1, 1, 1, 0, -1 };
+ const int wall_x = (int)G.cam_pos[0] + xoff[i];
+ const int wall_z = (int)G.cam_pos[2] + zoff[i];
+ if (cube(wall_x, wall_z) < 1) {
+ continue;
+ }
+ }
+
+ // FOV mod
+ static float fov_mod = 0;
+ float fov_tgt = 0;
+ if (G.btns & BTN_FORWARD) {
+ fov_tgt += 15.0f;
+ }
+ if (G.btns & BTN_BACKWARD) {
+ fov_tgt -= 5.0f;
+ }
+ fov_mod = lerp(fov_mod, fov_tgt, G.dtime * 5.0f);
+
+ // Roll
+ static float cam_roll = 0;
+ float roll_tgt = 0;
+ if (G.btns & BTN_RIGHT) {
+ roll_tgt += 5.0f;
+ }
+ if (G.btns & BTN_LEFT) {
+ roll_tgt -= 5.0f;
+ }
+ cam_roll = lerp(cam_roll, roll_tgt, G.dtime * 5.0f);
+
+ // Update camera
+ G.cam_pos[1] = G.eye_height;
+ G.cam_fov = 75.0f + fov_mod;
+
+ // Light space matrix needed in both shaders
+ float lsm[16];
+ float sun_off[3] = { 5.214f, 20.0f, 8.143f };;
+
+ // Render pass: sun shadow map
+ GLCHECK(glBindFramebuffer(GL_FRAMEBUFFER, G.depth_fbo));
+ {
+ GLCHECK(glViewport(0, 0, G.depth_dim, G.depth_dim));
+ GLCHECK(glClear(GL_DEPTH_BUFFER_BIT));
+ GLCHECK(glUseProgram(G.world_depth_prog));
+
+ float proj[16]; orthographic4(proj, -25, 25, -25, 25, 5.0f, 40.0f);
+
+ float cam_up[3] = { 0.0f, 1.0f, 0.0f };
+
+ float sun[3];
+ addv3(sun, G.cam_pos, sun_off);
+ float look[16]; look4(look, sun, G.cam_pos, cam_up);
+
+ float view[16]; mul4(view, proj, look);
+
+ copy4(lsm, view);
+
+ render_scene(G.world_depth_prog, view, true);
+ }
+
+ // Render pass: First-person view
+ GLCHECK(glBindFramebuffer(GL_FRAMEBUFFER, 0));
+ {
+ GLCHECK(glViewport(0, 0, vp_w, vp_h));
+ GLCHECK(glClearColor(G.fog_color[0], G.fog_color[1], G.fog_color[2], 1.0f));
+ GLCHECK(glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT));
+ GLCHECK(glUseProgram(G.world_prog));
+
+ set_gluniform_3f(G.world_prog, "u_cam", G.cam_pos);
+ set_gluniform_1f(G.world_prog, "u_fog_start", G.fog_start_radius);
+ set_gluniform_1f(G.world_prog, "u_fog_end", G.fog_end_radius);
+ set_gluniform_3f(G.world_prog, "u_fog_color", G.fog_color);
+
+ GLCHECK(glActiveTexture(GL_TEXTURE1));
+ GLCHECK(glBindTexture(GL_TEXTURE_2D, G.depth_tex));
+ set_gluniform_1i(G.world_prog, "u_shadow_depth", 1);
+
+ set_gluniform_3f(G.world_prog, "u_sun", sun_off);
+ set_gluniform_m4(G.world_prog, "u_lightspace", lsm);
+
+ const float aspect = (float)vp_w / (float)vp_h;
+ float proj[16]; perspective4(proj, G.cam_fov, aspect, 0.1f, 100.0f);
+
+ float cam_fwd[3];
+ forward3(cam_fwd, G.cam_ang[0], G.cam_ang[1]);
+
+ float cam_tgt[3];
+ addv3(cam_tgt, G.cam_pos, cam_fwd);
+
+ float cam_up[3] = { 0.0f, 1.0f, 0.0f };
+ float cam_up_rot[3];
+ rotatev3(cam_up_rot, cam_up, cam_fwd, radians(cam_roll));
+
+ float look[16]; look4(look, G.cam_pos, cam_tgt, cam_up_rot);
+
+ float view[16]; mul4(view, proj, look);
+
+ render_scene(G.world_prog, view, false);
+ }
+
+ SDL_GL_SwapWindow(G.wnd);
+
+ return SDL_APP_CONTINUE;
+}
+
+static unsigned int keybind(SDL_Keycode key)
+{
+ switch (key) {
+ case SDLK_W: return BTN_FORWARD;
+ case SDLK_S: return BTN_BACKWARD;
+ case SDLK_A: return BTN_LEFT;
+ case SDLK_D: return BTN_RIGHT;
+ default: return 0;
+ };
+}
+
+SDL_AppResult SDL_AppEvent(void* appstate, SDL_Event* evt)
+{
+ UNUSED(appstate);
+
+ switch (evt->type) {
+ case SDL_EVENT_KEY_DOWN: {
+ if (evt->key.key == SDLK_ESCAPE) {
+ int ww = 0;
+ int wh = 0;
+ SDL_GetWindowSize(G.wnd, &ww, &wh);
+ SDL_WarpMouseInWindow(G.wnd, (float)ww / 2, (float)wh / 2);
+ SDL_SetWindowRelativeMouseMode(G.wnd, false);
+ }
+
+ G.btns |= keybind(evt->key.key);
+ } break;
+ case SDL_EVENT_KEY_UP: {
+ G.btns &= ~keybind(evt->key.key);
+ } break;
+ case SDL_EVENT_MOUSE_MOTION: {
+ if (SDL_GetWindowRelativeMouseMode(G.wnd)) {
+ const float sens = 0.1f;
+ G.cam_ang[0] += evt->motion.xrel * sens;
+ G.cam_ang[1] -= evt->motion.yrel * sens;
+ }
+ } break;
+ case SDL_EVENT_MOUSE_BUTTON_DOWN: {
+ if (!SDL_GetWindowRelativeMouseMode(G.wnd)) {
+ SDL_SetWindowRelativeMouseMode(G.wnd, true);
+ }
+ } break;
+ case SDL_EVENT_WINDOW_FOCUS_LOST: {
+ SDL_SetWindowRelativeMouseMode(G.wnd, false);
+ } break;
+ };
+
+ return (evt->type == SDL_EVENT_QUIT) ? SDL_APP_SUCCESS : SDL_APP_CONTINUE;
+}
+
+void SDL_AppQuit(void* appstate, SDL_AppResult result)
+{
+ UNUSED(appstate);
+ UNUSED(result);
+
+ SDL_DestroyWindow(G.wnd);
+}
+
generated by cgit v1.2.3 (git 2.46.0) at 2026-06-19 06:57:18 +0000