diff options
| -rw-r--r-- | main.c | 32 |
1 files changed, 19 insertions, 13 deletions
@@ -97,9 +97,11 @@ cs_src[] = "\n" PARTICLE_BUFFER "\n" + "uniform mediump float delta;\n" + "\n" "void main() {\n" " mediump uint i = gl_GlobalInvocationID.x;\n" - " positions[i] += 0.016 * velocities[i];\n" + " positions[i].xy += delta * velocities[i].xy;\n" "\n" " if (positions[i].x > 1.1) {\n" " positions[i].x -= 2.2;\n" @@ -359,16 +361,20 @@ init_particles(void) { static void update_particles( const GLuint ssbo, - const GLuint compute_prog + const GLuint compute_prog, + const GLint u_delta, + const float delta ) { if (USE_COMPUTE_SHADER) { UNUSED(ssbo); glUseProgram(compute_prog); + glUniform1f(u_delta, delta); glDispatchCompute(NUM_PARTICLES / WORKGROUP_SIZE, 1, 1); glMemoryBarrier(GL_SHADER_STORAGE_BARRIER_BIT); } else { UNUSED(compute_prog); + UNUSED(u_delta); // bind shader storage buffer glBindBuffer(GL_SHADER_STORAGE_BUFFER, ssbo); @@ -385,7 +391,7 @@ update_particles( #pragma omp parallel for for (int i = 0; i < NUM_PARTICLES; i++) { // update x coordinate - data->positions[4 * i + 0] += 0.016 * data->velocities[4 * i + 0]; + data->positions[4 * i + 0] += delta * data->velocities[4 * i + 0]; if (data->positions[4 * i + 0] < -1.1) { data->positions[4 * i + 0] += 2.2; } else if (data->positions[4 * i + 0] > 1.1) { @@ -393,7 +399,7 @@ update_particles( } // update y coordinate - data->positions[4 * i + 1] += 0.016 * data->velocities[4 * i + 1]; + data->positions[4 * i + 1] += delta * data->velocities[4 * i + 1]; if (data->positions[4 * i + 1] < -1.1) { data->positions[4 * i + 1] += 2.2; } else if (data->positions[4 * i + 1] > 1.1) { @@ -535,7 +541,7 @@ ctx_init(context_t * const ctx) { } // init times ring buffer - // memset(ctx->times, 0, sizeof(ctx->times)); + memset(ctx->times, 0, sizeof(ctx->times)); ctx->times_ofs = 0; // init flags @@ -669,26 +675,26 @@ int main(int argc, char *argv[]) { // unbind vao glBindVertexArray(0); - // link compute program + // link compute program, get uniform GLuint compute_prog = link_program(1, COMPUTE_SHADERS); - // TODO: need to pass delta in shader storage block eventually - // (for now it's hard-coded as 16ms in shader) - // GLint u_delta = glGetUniformLocation(compute_prog, "delta"); + GLint u_delta = glGetUniformLocation(compute_prog, "delta"); - // link render program, get uniforms + // link render program, get uniform GLuint render_prog = link_program(2, RENDER_SHADERS); GLint u_time = glGetUniformLocation(render_prog, "time"); // main loop while (!ctx.done) { - // get start time - uint32_t now = SDL_GetTicks(); + // get start time, then calculate delta + const uint32_t now = SDL_GetTicks(); + const uint32_t last_times_ofs = (ctx.times_ofs - 1) & (MAX_TIMES - 1); + const float delta = (now - ctx.times[last_times_ofs].draw_start) / 1000.0; // save start time ctx.times[ctx.times_ofs].draw_start = now; // update particles - update_particles(ssbo, compute_prog); + update_particles(ssbo, compute_prog, u_delta, delta); // clear screen glClearColor(0, 0, 0, 1); |