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Import .glb model file with animation

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- improve movement controls
- TODO: allow more than one model, instance, and animation
This commit is contained in:
var
2026-04-19 21:31:31 -05:00
parent 565c4e0e6f
commit 58289aa6b2
10 changed files with 9256 additions and 48 deletions
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168
src/render.c
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@@ -7,6 +7,7 @@
#define STB_IMAGE_IMPLEMENTATION
#include "stb/stb_image.h"
#include "cglm/cglm.h"
#include "cgltf/cgltf.h"
#include "render.h"
#include "camera.h"
#include "game.h"
@@ -125,15 +126,13 @@ static int CompileShader(GLchar *sourcePath, GLenum shaderType, char ***outCode,
return shaderId;
}
static int LoadShaders()
static int LoadShaders(const char *vertShaderFilePath, const char *fragShaderFilePath)
{
const char *vertShaderFilePath = "./res/glsl/vertex.glsl";
char **vertCode = NULL;
int vertNumLines;
int vertShaderId = CompileShader(vertShaderFilePath, GL_VERTEX_SHADER, &vertCode, &vertNumLines);
if (vertShaderId < 0) return vertShaderId;
const char *fragShaderFilePath = "./res/glsl/fragment.glsl";
char **fragCode = NULL;
int fragNumLines;
int fragShaderId = CompileShader(fragShaderFilePath, GL_FRAGMENT_SHADER, &fragCode, &fragNumLines);
@@ -223,9 +222,10 @@ bool Render_Init(GameState *gs)
printf("Created OpenGL window.\n");
glewInit();
gs->shaderProgramId = LoadShaders();
gs->shaderProgramId = LoadShaders("./res/glsl/vertex.glsl", "./res/glsl/fragment.glsl");
gs->modelShaderProgramId = LoadShaders("./res/glsl/model_vertex.glsl", "./res/glsl/fragment.glsl");
if (gs->shaderProgramId < 0)
if (gs->shaderProgramId < 0 || gs->modelShaderProgramId < 0)
{
printf("Failed to load shaders.\n");
return false;
@@ -238,7 +238,7 @@ bool Render_Init(GameState *gs)
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
printf("Initialized OpenGL.\n");
gs->numShapes = 3;
gs->numShapes = 2;
Shape *shape = Shape_MakePyramid(5);
gs->shapes[0] = shape;
@@ -256,27 +256,22 @@ bool Render_Init(GameState *gs)
glGenBuffers(1, &shape->EBO);
printf("Created shape 1.\n");
shape = Model_ReadObjFile("res/model/human.obj");
gs->shapes[2] = shape;
glGenVertexArrays(1, &shape->VAO);
glGenBuffers(1, &shape->VBO);
glGenBuffers(1, &shape->IBO);
glGenBuffers(1, &shape->EBO);
printf("Created shape 2.\n");
LoadTexture(gs);
printf("Loaded textures.\n");
Camera_Init(&gs->camera);
InitShapeBuffers(gs->shapes[0]);
InitShapeBuffers(gs->shapes[1]);
InitShapeBuffers(gs->shapes[2]);
printf("Initialized buffers.\n");
gs->testModel = Model_LoadGltf("res/model/human.glb");
return true;
}
void Render_Destroy(GameState *gs)
{
Model_Free(gs->testModel);
SDL_GL_DeleteContext(gs->glContext);
SDL_DestroyWindow(gs->window);
}
@@ -313,6 +308,132 @@ static void SetViewport(GameState *gs)
Camera_GetViewMatrix(&gs->camera, gs->viewMatrix);
}
static void Transform(ShapeInstance *instance, mat4 *matrix)
{
mat4 tempMat;
glm_mat4_identity(tempMat);
glm_translate(tempMat, instance->position);
glm_rotate_x(tempMat, instance->rotation[0], tempMat);
glm_rotate_y(tempMat, instance->rotation[1], tempMat);
glm_rotate_z(tempMat, instance->rotation[2], tempMat);
vec3 scale;
scale[0] = instance->scale;
scale[1] = instance->scale;
scale[2] = instance->scale;
glm_scale(tempMat, scale);
memcpy(matrix, tempMat, sizeof(mat4));
}
static void DrawModel(GameState *gs)
{
Model model = gs->testModel;
ShapeInstance instance = model.instance;
cgltf_data *data = model.data;
cgltf_skin *skin = model.skin;
cgltf_animation *anim = data->animations;
mat4 modelMatrix;
glm_mat4_identity(modelMatrix);
Transform(&model.instance, &modelMatrix);
uint64_t ticks = SDL_GetTicks();
float t = ticks / 1000.0f;
while (t > 2.0f) t -= 2.0f;
// apply local transformations for each bone for the current animation frame
for (int i = 0; i < anim->channels_count; i++)
{
cgltf_animation_channel* channel = &anim->channels[i];
cgltf_animation_sampler* sampler = channel->sampler;
cgltf_node* node = channel->target_node;
// find keyframe interval [k, k+1]
size_t k = 0;
float alpha = 0.0f;
size_t num_keyframes = sampler->input->count;
// binary search may be faster
for (size_t j = 0; j < num_keyframes - 1; ++j)
{
float t0, t1;
cgltf_accessor_read_float(sampler->input, j, &t0, 1);
cgltf_accessor_read_float(sampler->input, j + 1, &t1, 1);
if (t >= t0 && t <= t1)
{
k = j;
float range = t1 - t0;
alpha = (range > 0.0f) ? (t - t0) / range : 0.0f;
break;
}
}
// interpolate
switch (channel->target_path)
{
case cgltf_animation_path_type_translation:
{
vec3 p0, p1, result;
cgltf_accessor_read_float(sampler->output, k, p0, 3);
cgltf_accessor_read_float(sampler->output, k + 1, p1, 3);
glm_vec3_lerp(p0, p1, alpha, result);
// glm_vec3_copy is not used here due to potential struct alignment issues
for (int x = 0; x < 3; x++) node->translation[x] = result[x];
node->has_translation = true;
}
break;
case cgltf_animation_path_type_rotation:
{
versor q0, q1, result;
cgltf_accessor_read_float(sampler->output, k, q0, 4);
cgltf_accessor_read_float(sampler->output, k + 1, q1, 4);
// slerp (not lerp) for rotation
glm_quat_slerp(q0, q1, alpha, result);
for (int x = 0; x < 4; x++) node->rotation[x] = result[x];
node->has_rotation = true;
}
break;
case cgltf_animation_path_type_scale:
{
vec3 s0, s1, result;
cgltf_accessor_read_float(sampler->output, k, s0, 3);
cgltf_accessor_read_float(sampler->output, k + 1, s1, 3);
glm_vec3_lerp(s0, s1, alpha, result);
for (int x = 0; x < 3; x++) node->scale[x] = result[x];
node->has_scale = true;
}
break;
default:
break;
}
}
// recalculate the joint matrices
for (int i = 0; i < skin->joints_count; i++)
{
cgltf_node *joint = skin->joints[i];
cgltf_node_transform_world(joint, (float*)model.jointMatrices[i]);
mat4 inverseBind;
cgltf_accessor_read_float(skin->inverse_bind_matrices, i, (float*)inverseBind, 16);
glm_mat4_mul(model.jointMatrices[i], inverseBind, model.jointMatrices[i]);
}
int shaderId = gs->modelShaderProgramId;
glUseProgram(shaderId);
glUniformMatrix4fv(glGetUniformLocation(shaderId, "theModelMatrix"), 1, GL_FALSE, (void*)(modelMatrix));
glUniformMatrix4fv(glGetUniformLocation(shaderId, "theViewMatrix"), 1, GL_FALSE, (void*)(gs->viewMatrix));
glUniformMatrix4fv(glGetUniformLocation(shaderId, "theProjMatrix"), 1, GL_FALSE, (void*)(gs->projMatrix));
glUniformMatrix4fv(glGetUniformLocation(shaderId, "theJointMatrices"), 64, GL_FALSE, (void*)(model.jointMatrices));
glUniform1f(glGetUniformLocation(shaderId, "texIndex"), 6.0f);
glBindTexture(GL_TEXTURE_2D, gs->textureId);
glBindVertexArray(model.vao);
glDrawElements(GL_TRIANGLES, model.indexCount, GL_UNSIGNED_SHORT, 0);
}
void Render_Draw(GameState *gs)
{
glClearColor(0.4f, 0.6f, 0.8f, 1.0f);
@@ -338,20 +459,7 @@ void Render_Draw(GameState *gs)
{
ShapeInstance* instance = shape->instances + j;
mat4* matrix = (void*)(shape->instanceData + (j * 17) + 1);
mat4 tempMat;
glm_mat4_identity(tempMat);
glm_translate(tempMat, instance->position);
glm_rotate_x(tempMat, instance->rotation[0], tempMat);
glm_rotate_y(tempMat, instance->rotation[1], tempMat);
glm_rotate_z(tempMat, instance->rotation[2], tempMat);
scale[0] = instance->scale;
scale[1] = instance->scale;
scale[2] = instance->scale;
glm_scale(tempMat, scale);
memcpy(matrix, tempMat, sizeof(mat4));
Transform(instance, matrix);
}
// re-buffer the instance data because transformations may have changed
@@ -361,5 +469,7 @@ void Render_Draw(GameState *gs)
glDrawElementsInstanced(GL_TRIANGLES, shape->numIndices, GL_UNSIGNED_SHORT, 0, shape->numInstances);
}
DrawModel(gs);
SDL_GL_SwapWindow(gs->window);
}