From e77bbf48dea457f0dc179b58cdd39126b8cebda8 Mon Sep 17 00:00:00 2001 From: Ruben Date: Fri, 24 Feb 2023 15:49:56 +0100 Subject: [PATCH] Initial commit --- .gitignore | 98 +++++++ CMakeLists.txt | 36 +++ shaders/fragmentshader.frag | 7 + shaders/vertexshader.vert | 7 + src/gline.c | 72 +++++ src/gline.h | 14 + src/linmath.h | 567 ++++++++++++++++++++++++++++++++++++ src/shader.c | 92 ++++++ src/shader.h | 6 + 9 files changed, 899 insertions(+) create mode 100644 .gitignore create mode 100644 CMakeLists.txt create mode 100644 shaders/fragmentshader.frag create mode 100644 shaders/vertexshader.vert create mode 100644 src/gline.c create mode 100644 src/gline.h create mode 100644 src/linmath.h create mode 100644 src/shader.c create mode 100644 src/shader.h diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..b881975 --- /dev/null +++ b/.gitignore @@ -0,0 +1,98 @@ +# Created by https://www.toptal.com/developers/gitignore/api/c,cmake,vim +# Edit at https://www.toptal.com/developers/gitignore?templates=c,cmake,vim + +### C ### +# Prerequisites +*.d + +# Object files +*.o +*.ko +*.obj +*.elf + +# Linker output +*.ilk +*.map +*.exp + +# Precompiled Headers +*.gch +*.pch + +# Libraries +*.lib +*.a +*.la +*.lo + +# Shared objects (inc. Windows DLLs) +*.dll +*.so +*.so.* +*.dylib + +# Executables +*.exe +*.out +*.app +*.i*86 +*.x86_64 +*.hex + +# Debug files +*.dSYM/ +*.su +*.idb +*.pdb + +# Kernel Module Compile Results +*.mod* +*.cmd +.tmp_versions/ +modules.order +Module.symvers +Mkfile.old +dkms.conf + +### CMake ### +CMakeLists.txt.user +CMakeCache.txt +CMakeFiles +CMakeScripts +Testing +Makefile +cmake_install.cmake +install_manifest.txt +compile_commands.json +CTestTestfile.cmake +_deps + +### CMake Patch ### +# External projects +*-prefix/ + +### Vim ### +# Swap +[._]*.s[a-v][a-z] +!*.svg # comment out if you don't need vector files +[._]*.sw[a-p] +[._]s[a-rt-v][a-z] +[._]ss[a-gi-z] +[._]sw[a-p] + +# Session +Session.vim +Sessionx.vim + +# Temporary +.netrwhist +*~ +# Auto-generated tag files +tags +# Persistent undo +[._]*.un~ + +# End of https://www.toptal.com/developers/gitignore/api/c,cmake,vim + +build/ diff --git a/CMakeLists.txt b/CMakeLists.txt new file mode 100644 index 0000000..4ad27cf --- /dev/null +++ b/CMakeLists.txt @@ -0,0 +1,36 @@ +cmake_minimum_required(VERSION 3.10) + +project(gline C) + +set(OpenGL_GL_PREFERENCE "GLVND") +find_package(GLEW REQUIRED) +find_package(OpenGL REQUIRED) +find_package(GLU REQUIRED) + +set(GLEW_INCLUDE_PATH "" CACHE PATH "/usr/include/GL") +set(GLFW_INCLUDE_PATH "" CACHE PATH "/usr/include/GLFW") + +set(gline_HEADERS + src/gline.h + src/shader.h + src/linmath.h +) + +set(gline_SOURCES + src/gline.c + src/shader.c +) + +add_executable( + ${PROJECT_NAME} + ${gline_HEADERS} + ${gline_SOURCES} +) + +target_include_directories(${PROJECT_NAME} PRIVATE ${GLFW_INCLUDE_DIRS}) +target_link_libraries(${PROJECT_NAME} PRIVATE ${OPENGL_LIBRARIES} + ${GLU_LIBRARIES} GLEW::GLEW glfw m) + +set(CMAKE_BUILD_TYPE Debug) + +install(TARGETS ${PROJECT_NAME} RUNTIME DESTINATION bin) diff --git a/shaders/fragmentshader.frag b/shaders/fragmentshader.frag new file mode 100644 index 0000000..4ab23c8 --- /dev/null +++ b/shaders/fragmentshader.frag @@ -0,0 +1,7 @@ +#version 400 + +out vec4 frag_color; + +void main() { + frag_color = vec4(0.5, 0.0, 0.5, 1.0); +} diff --git a/shaders/vertexshader.vert b/shaders/vertexshader.vert new file mode 100644 index 0000000..07000bc --- /dev/null +++ b/shaders/vertexshader.vert @@ -0,0 +1,7 @@ +#version 400 + +in vec3 vp; + +void main() { + gl_Position = vec4(vp, 1.0); +} diff --git a/src/gline.c b/src/gline.c new file mode 100644 index 0000000..5d99fbb --- /dev/null +++ b/src/gline.c @@ -0,0 +1,72 @@ +#include "gline.h" + +int main(int argc, char **argv) { + if (!glfwInit()) { + fprintf(stderr, "ERROR: Could not start GLFW\n"); + return 1; + } + glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3); + glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3); + glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); + + GLFWwindow *window = glfwCreateWindow(640, 480, "Gline", NULL, NULL); + if (!window) { + fprintf(stderr, "ERROR: Could not open window\n"); + glfwTerminate(); + return 1; + } + glfwMakeContextCurrent(window); + + glewExperimental = GL_TRUE; + glewInit(); + + const GLubyte *renderer = glGetString(GL_RENDERER); + const GLubyte *version = glGetString(GL_VERSION); + printf("Renderer: %s\n", renderer); + printf("Version: %s\n", version); + + glEnable(GL_DEPTH_TEST); + glDepthFunc(GL_LESS); + + float points[] = {0.f, 0.5f, 0.f, 0.5f, -0.5f, 0.f, -0.5f, -0.5f, 0.f}; + + GLuint vbo = 0; + glGenBuffers(1, &vbo); + glBindBuffer(GL_ARRAY_BUFFER, vbo); + glBufferData(GL_ARRAY_BUFFER, 9 * sizeof(float), points, GL_STATIC_DRAW); + + GLuint vao = 0; + glGenVertexArrays(1, &vao); + glBindVertexArray(vao); + glEnableVertexAttribArray(0); + glBindBuffer(GL_ARRAY_BUFFER, vbo); + glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, NULL); + + const char *vert_source = shader_read_file("../shaders/vertexshader.vert"); + const char *frag_source = shader_read_file("../shaders/fragmentshader.frag"); + + GLuint vs = glCreateShader(GL_VERTEX_SHADER); + glShaderSource(vs, 1, &vert_source, NULL); + glCompileShader(vs); + GLuint fs = glCreateShader(GL_FRAGMENT_SHADER); + glShaderSource(fs, 1, &frag_source, NULL); + glCompileShader(fs); + + GLuint shader_prog = glCreateProgram(); + glAttachShader(shader_prog, fs); + glAttachShader(shader_prog, vs); + glLinkProgram(shader_prog); + + while (!glfwWindowShouldClose(window)) { + glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); + glUseProgram(shader_prog); + glBindVertexArray(vao); + glDrawArrays(GL_TRIANGLES, 0, 3); + glfwPollEvents(); + glfwSwapBuffers(window); + } + + glfwTerminate(); + + return 0; +} diff --git a/src/gline.h b/src/gline.h new file mode 100644 index 0000000..fc9aa83 --- /dev/null +++ b/src/gline.h @@ -0,0 +1,14 @@ +#ifndef GLINE_H_ +#define GLINE_H_ + +#include "linmath.h" +#include "shader.h" +#include +#include +#include +#include +#include + +int main(int argc, char **argv); + +#endif diff --git a/src/linmath.h b/src/linmath.h new file mode 100644 index 0000000..c87c8e2 --- /dev/null +++ b/src/linmath.h @@ -0,0 +1,567 @@ +#ifndef LINMATH_H +#define LINMATH_H + +#include +#include + +#ifdef LINMATH_NO_INLINE +#define LINMATH_H_FUNC static +#else +#define LINMATH_H_FUNC static inline +#endif + +#define LINMATH_H_DEFINE_VEC(n) \ + typedef float vec##n[n]; \ + LINMATH_H_FUNC void vec##n##_add(vec##n r, vec##n const a, vec##n const b) { \ + int i; \ + for (i = 0; i < n; ++i) \ + r[i] = a[i] + b[i]; \ + } \ + LINMATH_H_FUNC void vec##n##_sub(vec##n r, vec##n const a, vec##n const b) { \ + int i; \ + for (i = 0; i < n; ++i) \ + r[i] = a[i] - b[i]; \ + } \ + LINMATH_H_FUNC void vec##n##_scale(vec##n r, vec##n const v, \ + float const s) { \ + int i; \ + for (i = 0; i < n; ++i) \ + r[i] = v[i] * s; \ + } \ + LINMATH_H_FUNC float vec##n##_mul_inner(vec##n const a, vec##n const b) { \ + float p = 0.f; \ + int i; \ + for (i = 0; i < n; ++i) \ + p += b[i] * a[i]; \ + return p; \ + } \ + LINMATH_H_FUNC float vec##n##_len(vec##n const v) { \ + return sqrtf(vec##n##_mul_inner(v, v)); \ + } \ + LINMATH_H_FUNC void vec##n##_norm(vec##n r, vec##n const v) { \ + float k = 1.f / vec##n##_len(v); \ + vec##n##_scale(r, v, k); \ + } \ + LINMATH_H_FUNC void vec##n##_min(vec##n r, vec##n const a, vec##n const b) { \ + int i; \ + for (i = 0; i < n; ++i) \ + r[i] = a[i] < b[i] ? a[i] : b[i]; \ + } \ + LINMATH_H_FUNC void vec##n##_max(vec##n r, vec##n const a, vec##n const b) { \ + int i; \ + for (i = 0; i < n; ++i) \ + r[i] = a[i] > b[i] ? a[i] : b[i]; \ + } \ + LINMATH_H_FUNC void vec##n##_dup(vec##n r, vec##n const src) { \ + int i; \ + for (i = 0; i < n; ++i) \ + r[i] = src[i]; \ + } + +LINMATH_H_DEFINE_VEC(2) +LINMATH_H_DEFINE_VEC(3) +LINMATH_H_DEFINE_VEC(4) + +LINMATH_H_FUNC void vec3_mul_cross(vec3 r, vec3 const a, vec3 const b) { + r[0] = a[1] * b[2] - a[2] * b[1]; + r[1] = a[2] * b[0] - a[0] * b[2]; + r[2] = a[0] * b[1] - a[1] * b[0]; +} + +LINMATH_H_FUNC void vec3_reflect(vec3 r, vec3 const v, vec3 const n) { + float p = 2.f * vec3_mul_inner(v, n); + int i; + for (i = 0; i < 3; ++i) + r[i] = v[i] - p * n[i]; +} + +LINMATH_H_FUNC void vec4_mul_cross(vec4 r, vec4 const a, vec4 const b) { + r[0] = a[1] * b[2] - a[2] * b[1]; + r[1] = a[2] * b[0] - a[0] * b[2]; + r[2] = a[0] * b[1] - a[1] * b[0]; + r[3] = 1.f; +} + +LINMATH_H_FUNC void vec4_reflect(vec4 r, vec4 const v, vec4 const n) { + float p = 2.f * vec4_mul_inner(v, n); + int i; + for (i = 0; i < 4; ++i) + r[i] = v[i] - p * n[i]; +} + +typedef vec4 mat4x4[4]; +LINMATH_H_FUNC void mat4x4_identity(mat4x4 M) { + int i, j; + for (i = 0; i < 4; ++i) + for (j = 0; j < 4; ++j) + M[i][j] = i == j ? 1.f : 0.f; +} +LINMATH_H_FUNC void mat4x4_dup(mat4x4 M, mat4x4 const N) { + int i; + for (i = 0; i < 4; ++i) + vec4_dup(M[i], N[i]); +} +LINMATH_H_FUNC void mat4x4_row(vec4 r, mat4x4 const M, int i) { + int k; + for (k = 0; k < 4; ++k) + r[k] = M[k][i]; +} +LINMATH_H_FUNC void mat4x4_col(vec4 r, mat4x4 const M, int i) { + int k; + for (k = 0; k < 4; ++k) + r[k] = M[i][k]; +} +LINMATH_H_FUNC void mat4x4_transpose(mat4x4 M, mat4x4 const N) { + // Note: if M and N are the same, the user has to + // explicitly make a copy of M and set it to N. + int i, j; + for (j = 0; j < 4; ++j) + for (i = 0; i < 4; ++i) + M[i][j] = N[j][i]; +} +LINMATH_H_FUNC void mat4x4_add(mat4x4 M, mat4x4 const a, mat4x4 const b) { + int i; + for (i = 0; i < 4; ++i) + vec4_add(M[i], a[i], b[i]); +} +LINMATH_H_FUNC void mat4x4_sub(mat4x4 M, mat4x4 const a, mat4x4 const b) { + int i; + for (i = 0; i < 4; ++i) + vec4_sub(M[i], a[i], b[i]); +} +LINMATH_H_FUNC void mat4x4_scale(mat4x4 M, mat4x4 const a, float k) { + int i; + for (i = 0; i < 4; ++i) + vec4_scale(M[i], a[i], k); +} +LINMATH_H_FUNC void mat4x4_scale_aniso(mat4x4 M, mat4x4 const a, float x, + float y, float z) { + vec4_scale(M[0], a[0], x); + vec4_scale(M[1], a[1], y); + vec4_scale(M[2], a[2], z); + vec4_dup(M[3], a[3]); +} +LINMATH_H_FUNC void mat4x4_mul(mat4x4 M, mat4x4 const a, mat4x4 const b) { + mat4x4 temp; + int k, r, c; + for (c = 0; c < 4; ++c) + for (r = 0; r < 4; ++r) { + temp[c][r] = 0.f; + for (k = 0; k < 4; ++k) + temp[c][r] += a[k][r] * b[c][k]; + } + mat4x4_dup(M, temp); +} +LINMATH_H_FUNC void mat4x4_mul_vec4(vec4 r, mat4x4 const M, vec4 const v) { + int i, j; + for (j = 0; j < 4; ++j) { + r[j] = 0.f; + for (i = 0; i < 4; ++i) + r[j] += M[i][j] * v[i]; + } +} +LINMATH_H_FUNC void mat4x4_translate(mat4x4 T, float x, float y, float z) { + mat4x4_identity(T); + T[3][0] = x; + T[3][1] = y; + T[3][2] = z; +} +LINMATH_H_FUNC void mat4x4_translate_in_place(mat4x4 M, float x, float y, + float z) { + vec4 t = {x, y, z, 0}; + vec4 r; + int i; + for (i = 0; i < 4; ++i) { + mat4x4_row(r, M, i); + M[3][i] += vec4_mul_inner(r, t); + } +} +LINMATH_H_FUNC void mat4x4_from_vec3_mul_outer(mat4x4 M, vec3 const a, + vec3 const b) { + int i, j; + for (i = 0; i < 4; ++i) + for (j = 0; j < 4; ++j) + M[i][j] = i < 3 && j < 3 ? a[i] * b[j] : 0.f; +} +LINMATH_H_FUNC void mat4x4_rotate(mat4x4 R, mat4x4 const M, float x, float y, + float z, float angle) { + float s = sinf(angle); + float c = cosf(angle); + vec3 u = {x, y, z}; + + if (vec3_len(u) > 1e-4) { + vec3_norm(u, u); + mat4x4 T; + mat4x4_from_vec3_mul_outer(T, u, u); + + mat4x4 S = {{0, u[2], -u[1], 0}, + {-u[2], 0, u[0], 0}, + {u[1], -u[0], 0, 0}, + {0, 0, 0, 0}}; + mat4x4_scale(S, S, s); + + mat4x4 C; + mat4x4_identity(C); + mat4x4_sub(C, C, T); + + mat4x4_scale(C, C, c); + + mat4x4_add(T, T, C); + mat4x4_add(T, T, S); + + T[3][3] = 1.f; + mat4x4_mul(R, M, T); + } else { + mat4x4_dup(R, M); + } +} +LINMATH_H_FUNC void mat4x4_rotate_X(mat4x4 Q, mat4x4 const M, float angle) { + float s = sinf(angle); + float c = cosf(angle); + mat4x4 R = {{1.f, 0.f, 0.f, 0.f}, + {0.f, c, s, 0.f}, + {0.f, -s, c, 0.f}, + {0.f, 0.f, 0.f, 1.f}}; + mat4x4_mul(Q, M, R); +} +LINMATH_H_FUNC void mat4x4_rotate_Y(mat4x4 Q, mat4x4 const M, float angle) { + float s = sinf(angle); + float c = cosf(angle); + mat4x4 R = {{c, 0.f, -s, 0.f}, + {0.f, 1.f, 0.f, 0.f}, + {s, 0.f, c, 0.f}, + {0.f, 0.f, 0.f, 1.f}}; + mat4x4_mul(Q, M, R); +} +LINMATH_H_FUNC void mat4x4_rotate_Z(mat4x4 Q, mat4x4 const M, float angle) { + float s = sinf(angle); + float c = cosf(angle); + mat4x4 R = {{c, s, 0.f, 0.f}, + {-s, c, 0.f, 0.f}, + {0.f, 0.f, 1.f, 0.f}, + {0.f, 0.f, 0.f, 1.f}}; + mat4x4_mul(Q, M, R); +} +LINMATH_H_FUNC void mat4x4_invert(mat4x4 T, mat4x4 const M) { + float s[6]; + float c[6]; + s[0] = M[0][0] * M[1][1] - M[1][0] * M[0][1]; + s[1] = M[0][0] * M[1][2] - M[1][0] * M[0][2]; + s[2] = M[0][0] * M[1][3] - M[1][0] * M[0][3]; + s[3] = M[0][1] * M[1][2] - M[1][1] * M[0][2]; + s[4] = M[0][1] * M[1][3] - M[1][1] * M[0][3]; + s[5] = M[0][2] * M[1][3] - M[1][2] * M[0][3]; + + c[0] = M[2][0] * M[3][1] - M[3][0] * M[2][1]; + c[1] = M[2][0] * M[3][2] - M[3][0] * M[2][2]; + c[2] = M[2][0] * M[3][3] - M[3][0] * M[2][3]; + c[3] = M[2][1] * M[3][2] - M[3][1] * M[2][2]; + c[4] = M[2][1] * M[3][3] - M[3][1] * M[2][3]; + c[5] = M[2][2] * M[3][3] - M[3][2] * M[2][3]; + + /* Assumes it is invertible */ + float idet = 1.0f / (s[0] * c[5] - s[1] * c[4] + s[2] * c[3] + s[3] * c[2] - + s[4] * c[1] + s[5] * c[0]); + + T[0][0] = (M[1][1] * c[5] - M[1][2] * c[4] + M[1][3] * c[3]) * idet; + T[0][1] = (-M[0][1] * c[5] + M[0][2] * c[4] - M[0][3] * c[3]) * idet; + T[0][2] = (M[3][1] * s[5] - M[3][2] * s[4] + M[3][3] * s[3]) * idet; + T[0][3] = (-M[2][1] * s[5] + M[2][2] * s[4] - M[2][3] * s[3]) * idet; + + T[1][0] = (-M[1][0] * c[5] + M[1][2] * c[2] - M[1][3] * c[1]) * idet; + T[1][1] = (M[0][0] * c[5] - M[0][2] * c[2] + M[0][3] * c[1]) * idet; + T[1][2] = (-M[3][0] * s[5] + M[3][2] * s[2] - M[3][3] * s[1]) * idet; + T[1][3] = (M[2][0] * s[5] - M[2][2] * s[2] + M[2][3] * s[1]) * idet; + + T[2][0] = (M[1][0] * c[4] - M[1][1] * c[2] + M[1][3] * c[0]) * idet; + T[2][1] = (-M[0][0] * c[4] + M[0][1] * c[2] - M[0][3] * c[0]) * idet; + T[2][2] = (M[3][0] * s[4] - M[3][1] * s[2] + M[3][3] * s[0]) * idet; + T[2][3] = (-M[2][0] * s[4] + M[2][1] * s[2] - M[2][3] * s[0]) * idet; + + T[3][0] = (-M[1][0] * c[3] + M[1][1] * c[1] - M[1][2] * c[0]) * idet; + T[3][1] = (M[0][0] * c[3] - M[0][1] * c[1] + M[0][2] * c[0]) * idet; + T[3][2] = (-M[3][0] * s[3] + M[3][1] * s[1] - M[3][2] * s[0]) * idet; + T[3][3] = (M[2][0] * s[3] - M[2][1] * s[1] + M[2][2] * s[0]) * idet; +} +LINMATH_H_FUNC void mat4x4_orthonormalize(mat4x4 R, mat4x4 const M) { + mat4x4_dup(R, M); + float s = 1.f; + vec3 h; + + vec3_norm(R[2], R[2]); + + s = vec3_mul_inner(R[1], R[2]); + vec3_scale(h, R[2], s); + vec3_sub(R[1], R[1], h); + vec3_norm(R[1], R[1]); + + s = vec3_mul_inner(R[0], R[2]); + vec3_scale(h, R[2], s); + vec3_sub(R[0], R[0], h); + + s = vec3_mul_inner(R[0], R[1]); + vec3_scale(h, R[1], s); + vec3_sub(R[0], R[0], h); + vec3_norm(R[0], R[0]); +} + +LINMATH_H_FUNC void mat4x4_frustum(mat4x4 M, float l, float r, float b, float t, + float n, float f) { + M[0][0] = 2.f * n / (r - l); + M[0][1] = M[0][2] = M[0][3] = 0.f; + + M[1][1] = 2.f * n / (t - b); + M[1][0] = M[1][2] = M[1][3] = 0.f; + + M[2][0] = (r + l) / (r - l); + M[2][1] = (t + b) / (t - b); + M[2][2] = -(f + n) / (f - n); + M[2][3] = -1.f; + + M[3][2] = -2.f * (f * n) / (f - n); + M[3][0] = M[3][1] = M[3][3] = 0.f; +} +LINMATH_H_FUNC void mat4x4_ortho(mat4x4 M, float l, float r, float b, float t, + float n, float f) { + M[0][0] = 2.f / (r - l); + M[0][1] = M[0][2] = M[0][3] = 0.f; + + M[1][1] = 2.f / (t - b); + M[1][0] = M[1][2] = M[1][3] = 0.f; + + M[2][2] = -2.f / (f - n); + M[2][0] = M[2][1] = M[2][3] = 0.f; + + M[3][0] = -(r + l) / (r - l); + M[3][1] = -(t + b) / (t - b); + M[3][2] = -(f + n) / (f - n); + M[3][3] = 1.f; +} +LINMATH_H_FUNC void mat4x4_perspective(mat4x4 m, float y_fov, float aspect, + float n, float f) { + /* NOTE: Degrees are an unhandy unit to work with. + * linmath.h uses radians for everything! */ + float const a = 1.f / tanf(y_fov / 2.f); + + m[0][0] = a / aspect; + m[0][1] = 0.f; + m[0][2] = 0.f; + m[0][3] = 0.f; + + m[1][0] = 0.f; + m[1][1] = a; + m[1][2] = 0.f; + m[1][3] = 0.f; + + m[2][0] = 0.f; + m[2][1] = 0.f; + m[2][2] = -((f + n) / (f - n)); + m[2][3] = -1.f; + + m[3][0] = 0.f; + m[3][1] = 0.f; + m[3][2] = -((2.f * f * n) / (f - n)); + m[3][3] = 0.f; +} +LINMATH_H_FUNC void mat4x4_look_at(mat4x4 m, vec3 const eye, vec3 const center, + vec3 const up) { + /* Adapted from Android's OpenGL Matrix.java. */ + /* See the OpenGL GLUT documentation for gluLookAt for a description */ + /* of the algorithm. We implement it in a straightforward way: */ + + /* TODO: The negation of of can be spared by swapping the order of + * operands in the following cross products in the right way. */ + vec3 f; + vec3_sub(f, center, eye); + vec3_norm(f, f); + + vec3 s; + vec3_mul_cross(s, f, up); + vec3_norm(s, s); + + vec3 t; + vec3_mul_cross(t, s, f); + + m[0][0] = s[0]; + m[0][1] = t[0]; + m[0][2] = -f[0]; + m[0][3] = 0.f; + + m[1][0] = s[1]; + m[1][1] = t[1]; + m[1][2] = -f[1]; + m[1][3] = 0.f; + + m[2][0] = s[2]; + m[2][1] = t[2]; + m[2][2] = -f[2]; + m[2][3] = 0.f; + + m[3][0] = 0.f; + m[3][1] = 0.f; + m[3][2] = 0.f; + m[3][3] = 1.f; + + mat4x4_translate_in_place(m, -eye[0], -eye[1], -eye[2]); +} + +typedef float quat[4]; +#define quat_add vec4_add +#define quat_sub vec4_sub +#define quat_norm vec4_norm +#define quat_scale vec4_scale +#define quat_mul_inner vec4_mul_inner + +LINMATH_H_FUNC void quat_identity(quat q) { + q[0] = q[1] = q[2] = 0.f; + q[3] = 1.f; +} +LINMATH_H_FUNC void quat_mul(quat r, quat const p, quat const q) { + vec3 w, tmp; + + vec3_mul_cross(tmp, p, q); + vec3_scale(w, p, q[3]); + vec3_add(tmp, tmp, w); + vec3_scale(w, q, p[3]); + vec3_add(tmp, tmp, w); + + vec3_dup(r, tmp); + r[3] = p[3] * q[3] - vec3_mul_inner(p, q); +} +LINMATH_H_FUNC void quat_conj(quat r, quat const q) { + int i; + for (i = 0; i < 3; ++i) + r[i] = -q[i]; + r[3] = q[3]; +} +LINMATH_H_FUNC void quat_rotate(quat r, float angle, vec3 const axis) { + vec3 axis_norm; + vec3_norm(axis_norm, axis); + float s = sinf(angle / 2); + float c = cosf(angle / 2); + vec3_scale(r, axis_norm, s); + r[3] = c; +} +LINMATH_H_FUNC void quat_mul_vec3(vec3 r, quat const q, vec3 const v) { + /* + * Method by Fabian 'ryg' Giessen (of Farbrausch) + t = 2 * cross(q.xyz, v) + v' = v + q.w * t + cross(q.xyz, t) + */ + vec3 t; + vec3 q_xyz = {q[0], q[1], q[2]}; + vec3 u = {q[0], q[1], q[2]}; + + vec3_mul_cross(t, q_xyz, v); + vec3_scale(t, t, 2); + + vec3_mul_cross(u, q_xyz, t); + vec3_scale(t, t, q[3]); + + vec3_add(r, v, t); + vec3_add(r, r, u); +} +LINMATH_H_FUNC void mat4x4_from_quat(mat4x4 M, quat const q) { + float a = q[3]; + float b = q[0]; + float c = q[1]; + float d = q[2]; + float a2 = a * a; + float b2 = b * b; + float c2 = c * c; + float d2 = d * d; + + M[0][0] = a2 + b2 - c2 - d2; + M[0][1] = 2.f * (b * c + a * d); + M[0][2] = 2.f * (b * d - a * c); + M[0][3] = 0.f; + + M[1][0] = 2 * (b * c - a * d); + M[1][1] = a2 - b2 + c2 - d2; + M[1][2] = 2.f * (c * d + a * b); + M[1][3] = 0.f; + + M[2][0] = 2.f * (b * d + a * c); + M[2][1] = 2.f * (c * d - a * b); + M[2][2] = a2 - b2 - c2 + d2; + M[2][3] = 0.f; + + M[3][0] = M[3][1] = M[3][2] = 0.f; + M[3][3] = 1.f; +} + +LINMATH_H_FUNC void mat4x4o_mul_quat(mat4x4 R, mat4x4 const M, quat const q) { + /* XXX: The way this is written only works for orthogonal matrices. */ + /* TODO: Take care of non-orthogonal case. */ + quat_mul_vec3(R[0], q, M[0]); + quat_mul_vec3(R[1], q, M[1]); + quat_mul_vec3(R[2], q, M[2]); + + R[3][0] = R[3][1] = R[3][2] = 0.f; + R[0][3] = M[0][3]; + R[1][3] = M[1][3]; + R[2][3] = M[2][3]; + R[3][3] = M[3][3]; // typically 1.0, but here we make it general +} +LINMATH_H_FUNC void quat_from_mat4x4(quat q, mat4x4 const M) { + float r = 0.f; + int i; + + int perm[] = {0, 1, 2, 0, 1}; + int *p = perm; + + for (i = 0; i < 3; i++) { + float m = M[i][i]; + if (m < r) + continue; + m = r; + p = &perm[i]; + } + + r = sqrtf(1.f + M[p[0]][p[0]] - M[p[1]][p[1]] - M[p[2]][p[2]]); + + if (r < 1e-6) { + q[0] = 1.f; + q[1] = q[2] = q[3] = 0.f; + return; + } + + q[0] = r / 2.f; + q[1] = (M[p[0]][p[1]] - M[p[1]][p[0]]) / (2.f * r); + q[2] = (M[p[2]][p[0]] - M[p[0]][p[2]]) / (2.f * r); + q[3] = (M[p[2]][p[1]] - M[p[1]][p[2]]) / (2.f * r); +} + +LINMATH_H_FUNC void mat4x4_arcball(mat4x4 R, mat4x4 const M, vec2 const _a, + vec2 const _b, float s) { + vec2 a; + memcpy(a, _a, sizeof(a)); + vec2 b; + memcpy(b, _b, sizeof(b)); + + float z_a = 0.; + float z_b = 0.; + + if (vec2_len(a) < 1.) { + z_a = sqrtf(1. - vec2_mul_inner(a, a)); + } else { + vec2_norm(a, a); + } + + if (vec2_len(b) < 1.) { + z_b = sqrtf(1. - vec2_mul_inner(b, b)); + } else { + vec2_norm(b, b); + } + + vec3 a_ = {a[0], a[1], z_a}; + vec3 b_ = {b[0], b[1], z_b}; + + vec3 c_; + vec3_mul_cross(c_, a_, b_); + + float const angle = acos(vec3_mul_inner(a_, b_)) * s; + mat4x4_rotate(R, M, c_[0], c_[1], c_[2], angle); +} +#endif + diff --git a/src/shader.c b/src/shader.c new file mode 100644 index 0000000..6f32ec1 --- /dev/null +++ b/src/shader.c @@ -0,0 +1,92 @@ +#include "shader.h" + +char *shader_read_file(const char *file_path) { + FILE *fp; + char *buf; + long file_size; + fp = fopen(file_path, "r"); + if (fp == NULL) { + fprintf(stderr, "Failed to open file: %s\n", file_path); + return (char *)NULL; + } + fseek(fp, 0, SEEK_END); + file_size = ftell(fp); + fseek(fp, 0, SEEK_SET); + + buf = (char *)malloc(file_size + 1); + if (buf == NULL) { + fprintf(stderr, "Failed to allocate memory\n"); + fclose(fp); + return (char *)NULL; + } + fread(buf, file_size, 1, fp); + buf[file_size] = '\0'; + fclose(fp); + return buf; +} + +GLuint load_shader(const char *vfp, const char *ffp) { + GLuint vertex_id = glCreateShader(GL_VERTEX_SHADER); + GLuint fragment_id = glCreateShader(GL_FRAGMENT_SHADER); + char *err = (char *)malloc(sizeof(char *)); + char *v_source = shader_read_file(vfp); + char *f_source = shader_read_file(ffp); + + if (v_source == NULL) { + fprintf(stderr, "An error occurred\n"); + return (GLuint)0; + } + if (f_source == NULL) { + fprintf(stderr, "An error occurred\n"); + return (GLuint)0; + } + + GLint result = GL_FALSE; + int info_log_len; + + printf("Compiling shader: %s\n", vfp); + char const *vc_source = v_source; + glShaderSource(vertex_id, 1, &vc_source, NULL); + glCompileShader(vertex_id); + glGetShaderiv(vertex_id, GL_COMPILE_STATUS, &result); + glGetShaderiv(vertex_id, GL_INFO_LOG_LENGTH, &info_log_len); + if (info_log_len > 0) { + glGetShaderInfoLog(vertex_id, info_log_len, NULL, err); + puts(err); + } + + printf("Compiling shader: %s\n", ffp); + char const *fc_source = f_source; + + glShaderSource(fragment_id, 1, &fc_source, NULL); + glCompileShader(fragment_id); + glGetShaderiv(fragment_id, GL_COMPILE_STATUS, &result); + glGetShaderiv(vertex_id, GL_INFO_LOG_LENGTH, &info_log_len); + if (info_log_len > 0) { + glGetShaderInfoLog(fragment_id, info_log_len, NULL, err); + puts(err); + } + free(v_source); + free(f_source); + + puts("Linking program"); + GLuint pid = glCreateProgram(); + glAttachShader(pid, vertex_id); + glAttachShader(pid, fragment_id); + glLinkProgram(pid); + + glGetProgramiv(pid, GL_LINK_STATUS, &result); + glGetProgramiv(pid, GL_INFO_LOG_LENGTH, &info_log_len); + if (info_log_len > 0) { + glGetShaderInfoLog(pid, info_log_len, NULL, err); + puts(err); + } + free(err); + + glDetachShader(pid, vertex_id); + glDetachShader(pid, fragment_id); + glDeleteShader(vertex_id); + glDeleteShader(fragment_id); + + return pid; +} diff --git a/src/shader.h b/src/shader.h new file mode 100644 index 0000000..88f1c6f --- /dev/null +++ b/src/shader.h @@ -0,0 +1,6 @@ +#include +#include +#include + +char *shader_read_file(const char *file_path); +GLuint load_shader(const char *vfp, const char *ffp);