path: root/platform_opengl.c

/*
 * This is now a 7-pass shader
 *
 * 1. Phosphor persistence at source resolution (346×270)
 * 2. Upscale and warp to viewport resolution without CRT effects → clean, sharp pixels
 * 3. Extract bloom from upscaled clean pixels (white pixels, not RGB subpixels)
 * 4. Blur the bloom vertically
 * 5. Blur the bloom horizontally
 * 6. CRT shader on original source with all the phosphor masks and scanlines
 * 7. Composite warped bloom on top of the CRT effect
 *
 */

#include "shader.c"
#include "shader.h"

INCBIN_SHADER_NOHEADER(vertex_shader,						"#version 330", "shaders/gl_vertex.glsl");
INCBIN_SHADER(fragment_shader,								"#version 330", "shader.h", "shaders/gl_crt_fragment.glsl");
INCBIN_SHADER_NOHEADER(phosphor_persistence_fragment,	"#version 330", "shaders/gl_phosphor_persistence_fragment.glsl");
INCBIN_SHADER_NOHEADER(upscale_warp_fragment,			"#version 330", "shaders/gl_upscale_warp_fragment.glsl");
INCBIN_SHADER_NOHEADER(bloom_extract_fragment,			"#version 330", "shaders/gl_bloom_extract_fragment.glsl");
INCBIN_SHADER_NOHEADER(bloom_blur_fragment,				"#version 330", "shaders/gl_bloom_blur_fragment.glsl");
INCBIN_SHADER_NOHEADER(bloom_composite_fragment,		"#version 330", "shaders/gl_bloom_composite_fragment.glsl");

// [=]===^=[ cleanup_render_targets ]=============================================================^===[=]
static void cleanup_render_targets(void) {
	// Don't delete state.texture or persistence textures here - they're managed by change_resolution()
	glDeleteTextures(1, &state.crt_output_texture);
	glDeleteTextures(1, &state.bloom_texture);
	glDeleteTextures(1, &state.bloom_temp_texture);
	glDeleteTextures(1, &state.bloom_warped_texture);
	glDeleteTextures(1, &state.upscaled_source_texture);
	glDeleteFramebuffers(1, &state.crt_fbo);
	glDeleteFramebuffers(1, &state.bloom_fbo);
	glDeleteFramebuffers(1, &state.bloom_temp_fbo);
	glDeleteFramebuffers(1, &state.bloom_warp_fbo);
	glDeleteFramebuffers(1, &state.upscaled_source_fbo);
}

// [=]===^=[ setup_render_target ]================================================================^===[=]
static void setup_render_targets(void) {
	cleanup_render_targets();

	// Ensure source texture exists (might not if framebuffer_callback called before change_resolution)
	if(state.texture == 0 && state.render_width > 0 && state.render_height > 0) {
		GLfloat border_color[] = {0.0f, 0.0f, 0.0f, 1.0f};
		glGenTextures(1, &state.texture);
		glBindTexture(GL_TEXTURE_2D, state.texture);
		glTexImage2D(GL_TEXTURE_2D, 0, GL_SRGB8_ALPHA8, state.render_width, state.render_height, 0, GL_RGBA, GL_UNSIGNED_INT_8_8_8_8, NULL);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
		glTexParameterfv(GL_TEXTURE_2D, GL_TEXTURE_BORDER_COLOR, border_color);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
	}

	// Ensure persistence textures exist (created in change_resolution, not recreated on viewport change)
	if(state.persistence_texture == 0 && state.render_width > 0 && state.render_height > 0) {
		glGenTextures(1, &state.persistence_texture);
		glBindTexture(GL_TEXTURE_2D, state.persistence_texture);
		glTexImage2D(GL_TEXTURE_2D, 0, GL_SRGB8_ALPHA8, state.render_width, state.render_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

		glGenTextures(1, &state.persistence_output_texture);
		glBindTexture(GL_TEXTURE_2D, state.persistence_output_texture);
		glTexImage2D(GL_TEXTURE_2D, 0, GL_SRGB8_ALPHA8, state.render_width, state.render_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

		glGenFramebuffers(1, &state.persistence_fbo);
		glBindFramebuffer(GL_FRAMEBUFFER, state.persistence_fbo);
		glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, state.persistence_output_texture, 0);
		if(glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
			DEBUG_PRINT("Persistence FBO not complete!\n");
		}
		glBindFramebuffer(GL_FRAMEBUFFER, 0);
	}

	// CRT output texture (full viewport resolution)
	glGenTextures(1, &state.crt_output_texture);
	glBindTexture(GL_TEXTURE_2D, state.crt_output_texture);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_SRGB8_ALPHA8, state.viewport.w, state.viewport.h, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

	// Bloom textures (half resolution for wider blur spread)
	state.bloom_width = state.viewport.w / 1;
	state.bloom_height = state.viewport.h / 1;

	glGenTextures(1, &state.bloom_texture);
	glBindTexture(GL_TEXTURE_2D, state.bloom_texture);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F, state.bloom_width, state.bloom_height, 0, GL_RGBA, GL_FLOAT, NULL);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

	glGenTextures(1, &state.bloom_temp_texture);
	glBindTexture(GL_TEXTURE_2D, state.bloom_temp_texture);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F, state.bloom_width, state.bloom_height, 0, GL_RGBA, GL_FLOAT, NULL);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
	GLfloat black_border[] = {0.0f, 0.0f, 0.0f, 0.0f};
	glTexParameterfv(GL_TEXTURE_2D, GL_TEXTURE_BORDER_COLOR, black_border);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

	glGenTextures(1, &state.bloom_warped_texture);
	glBindTexture(GL_TEXTURE_2D, state.bloom_warped_texture);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F, state.bloom_width, state.bloom_height, 0, GL_RGBA, GL_FLOAT, NULL);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

	glBindTexture(GL_TEXTURE_2D, 0);

	// Create framebuffers
	glGenFramebuffers(1, &state.crt_fbo);
	glBindFramebuffer(GL_FRAMEBUFFER, state.crt_fbo);
	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, state.crt_output_texture, 0);
	if(glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
		DEBUG_PRINT("CRT FBO not complete!\n");
	}

	glGenFramebuffers(1, &state.bloom_fbo);
	glBindFramebuffer(GL_FRAMEBUFFER, state.bloom_fbo);
	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, state.bloom_texture, 0);
	if(glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
		DEBUG_PRINT("Bloom FBO not complete!\n");
	}

	glGenFramebuffers(1, &state.bloom_temp_fbo);
	glBindFramebuffer(GL_FRAMEBUFFER, state.bloom_temp_fbo);
	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, state.bloom_temp_texture, 0);
	if(glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
		DEBUG_PRINT("Bloom temp FBO not complete!\n");
	}

	glGenFramebuffers(1, &state.bloom_warp_fbo);
	glBindFramebuffer(GL_FRAMEBUFFER, state.bloom_warp_fbo);
	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, state.bloom_warped_texture, 0);
	if(glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
		DEBUG_PRINT("Bloom warp FBO not complete!\n");
	}

	// Upscaled source FBO (viewport resolution, for bloom extraction)
	glGenTextures(1, &state.upscaled_source_texture);
	glBindTexture(GL_TEXTURE_2D, state.upscaled_source_texture);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_SRGB8_ALPHA8, state.viewport.w, state.viewport.h, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

	glGenFramebuffers(1, &state.upscaled_source_fbo);
	glBindFramebuffer(GL_FRAMEBUFFER, state.upscaled_source_fbo);
	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, state.upscaled_source_texture, 0);
	if(glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
		DEBUG_PRINT("Upscaled source FBO not complete!\n");
	}

	glBindFramebuffer(GL_FRAMEBUFFER, 0);
}

// [=]===^=[ change_resolution ]=================================================================^===[=]
static void change_resolution(uint32_t new_width, uint32_t new_height) {
	state.render_width = new_width;
	state.render_height = new_height;

	// Recreate source texture
	GLfloat border_color[] = {0.0f, 0.0f, 0.0f, 1.0f};
	glDeleteTextures(1, &state.texture);
	glGenTextures(1, &state.texture);
	glBindTexture(GL_TEXTURE_2D, state.texture);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_SRGB8_ALPHA8, state.render_width, state.render_height, 0, GL_RGBA, GL_UNSIGNED_INT_8_8_8_8, NULL);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
	glTexParameterfv(GL_TEXTURE_2D, GL_TEXTURE_BORDER_COLOR, border_color);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

	// Recreate persistence textures (tied to source resolution)
	glDeleteTextures(1, &state.persistence_texture);
	glDeleteTextures(1, &state.persistence_output_texture);
	glDeleteFramebuffers(1, &state.persistence_fbo);

	glGenTextures(1, &state.persistence_texture);
	glBindTexture(GL_TEXTURE_2D, state.persistence_texture);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_SRGB8_ALPHA8, state.render_width, state.render_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

	glGenTextures(1, &state.persistence_output_texture);
	glBindTexture(GL_TEXTURE_2D, state.persistence_output_texture);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_SRGB8_ALPHA8, state.render_width, state.render_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

	glGenFramebuffers(1, &state.persistence_fbo);
	glBindFramebuffer(GL_FRAMEBUFFER, state.persistence_fbo);
	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, state.persistence_output_texture, 0);
	if(glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
		DEBUG_PRINT("Persistence FBO not complete!\n");
	}

	glBindTexture(GL_TEXTURE_2D, 0);
	glBindFramebuffer(GL_FRAMEBUFFER, 0);
}

// [=]===^=[ compile_shader ]==============================================================^===[=]
static GLuint compile_shader(GLenum shader_type, const char *shader_source) {
	GLuint shader = glCreateShader(shader_type);
	glShaderSource(shader, 1, &shader_source, 0);
	glCompileShader(shader);

	GLint success;
	GLchar info_log[512];
	glGetShaderiv(shader, GL_COMPILE_STATUS, &success);
	if(!success) {
		glGetShaderInfoLog(shader, sizeof(info_log), 0, info_log);
		DEBUG_PRINT("%s shader compilation failed:\n%s\n", (shader_type == GL_VERTEX_SHADER) ? "Vertex" : "Fragment", info_log);
	}
	return shader;
}

// [=]===^=[ opengl_setup ]================================================================^===[=]
static void opengl_setup(void) {
	gl_loader();
	glEnable(GL_FRAMEBUFFER_SRGB);
	glDisable(GL_DEPTH_TEST);
	glEnable(GL_BLEND);
	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
	glDisable(GL_CULL_FACE);

	// --- CRT Shader Setup ---
	GLuint main_vertex_shader = compile_shader(GL_VERTEX_SHADER, vertex_shader_data);
	GLuint main_fragment_shader = compile_shader(GL_FRAGMENT_SHADER, fragment_shader_data);
	state.shader_program = glCreateProgram();
	glAttachShader(state.shader_program, main_vertex_shader);
	glAttachShader(state.shader_program, main_fragment_shader);
	glBindAttribLocation(state.shader_program, 0, "position");
	glBindAttribLocation(state.shader_program, 1, "texture_coord");
	glLinkProgram(state.shader_program);
	glDeleteShader(main_vertex_shader);
	glDeleteShader(main_fragment_shader);

	// Initialize CRTS shader parameters
	state.contrast = 1.0f;
	state.saturation = 0.0f;
	state.brightness = 1.0f;
	CrtsTone(state.tone_data, state.contrast, state.saturation, INPUT_THIN, INPUT_MASK);

	glUseProgram(state.shader_program);
	state.uniform_resolution = glGetUniformLocation(state.shader_program, "resolution");
	state.uniform_src_image_size = glGetUniformLocation(state.shader_program, "src_image_size");
	state.uniform_brightness = glGetUniformLocation(state.shader_program, "brightness");
	state.uniform_tone = glGetUniformLocation(state.shader_program, "tone_data");
	state.uniform_crt_emulation = glGetUniformLocation(state.shader_program, "crt_emulation");
	state.uniform_apply_mask = glGetUniformLocation(state.shader_program, "apply_mask");
	state.uniform_sampler_location = glGetUniformLocation(state.shader_program, "iChannel0");

	// --- Phosphor Persistence Shader Setup ---
	GLuint persistence_vertex = compile_shader(GL_VERTEX_SHADER, vertex_shader_data);
	GLuint persistence_fragment = compile_shader(GL_FRAGMENT_SHADER, phosphor_persistence_fragment_data);
	state.persistence_program = glCreateProgram();
	glAttachShader(state.persistence_program, persistence_vertex);
	glAttachShader(state.persistence_program, persistence_fragment);
	glBindAttribLocation(state.persistence_program, 0, "position");
	glBindAttribLocation(state.persistence_program, 1, "texture_coord");
	glLinkProgram(state.persistence_program);
	glDeleteShader(persistence_vertex);
	glDeleteShader(persistence_fragment);

	// --- Upscale + Warp Shader Setup (for bloom path) ---
	GLuint upscale_warp_vertex = compile_shader(GL_VERTEX_SHADER, vertex_shader_data);
	GLuint upscale_warp_fragment = compile_shader(GL_FRAGMENT_SHADER, upscale_warp_fragment_data);
	state.upscale_warp_program = glCreateProgram();
	glAttachShader(state.upscale_warp_program, upscale_warp_vertex);
	glAttachShader(state.upscale_warp_program, upscale_warp_fragment);
	glBindAttribLocation(state.upscale_warp_program, 0, "position");
	glBindAttribLocation(state.upscale_warp_program, 1, "texture_coord");
	glLinkProgram(state.upscale_warp_program);
	glDeleteShader(upscale_warp_vertex);
	glDeleteShader(upscale_warp_fragment);

	// --- Bloom Extract Shader Setup ---
	GLuint bloom_extract_vertex = compile_shader(GL_VERTEX_SHADER, vertex_shader_data);
	GLuint bloom_extract_fragment = compile_shader(GL_FRAGMENT_SHADER, bloom_extract_fragment_data);
	state.bloom_extract_program = glCreateProgram();
	glAttachShader(state.bloom_extract_program, bloom_extract_vertex);
	glAttachShader(state.bloom_extract_program, bloom_extract_fragment);
	glBindAttribLocation(state.bloom_extract_program, 0, "position");
	glBindAttribLocation(state.bloom_extract_program, 1, "texture_coord");
	glLinkProgram(state.bloom_extract_program);
	glDeleteShader(bloom_extract_vertex);
	glDeleteShader(bloom_extract_fragment);

	glUseProgram(state.bloom_extract_program);
	state.bloom_uniform_threshold = glGetUniformLocation(state.bloom_extract_program, "threshold");
	state.bloom_uniform_sampler = glGetUniformLocation(state.bloom_extract_program, "source");

	// --- Bloom Blur Shader Setup ---
	GLuint bloom_blur_vertex = compile_shader(GL_VERTEX_SHADER, vertex_shader_data);
	GLuint bloom_blur_fragment = compile_shader(GL_FRAGMENT_SHADER, bloom_blur_fragment_data);
	state.bloom_blur_program = glCreateProgram();
	glAttachShader(state.bloom_blur_program, bloom_blur_vertex);
	glAttachShader(state.bloom_blur_program, bloom_blur_fragment);
	glBindAttribLocation(state.bloom_blur_program, 0, "position");
	glBindAttribLocation(state.bloom_blur_program, 1, "texture_coord");
	glLinkProgram(state.bloom_blur_program);
	glDeleteShader(bloom_blur_vertex);
	glDeleteShader(bloom_blur_fragment);

	glUseProgram(state.bloom_blur_program);
	state.blur_uniform_horizontal = glGetUniformLocation(state.bloom_blur_program, "horizontal");
	state.blur_uniform_sampler = glGetUniformLocation(state.bloom_blur_program, "source");

	// --- Bloom Composite Shader Setup ---
	GLuint bloom_composite_vertex = compile_shader(GL_VERTEX_SHADER, vertex_shader_data);
	GLuint bloom_composite_fragment = compile_shader(GL_FRAGMENT_SHADER, bloom_composite_fragment_data);
	state.bloom_composite_program = glCreateProgram();
	glAttachShader(state.bloom_composite_program, bloom_composite_vertex);
	glAttachShader(state.bloom_composite_program, bloom_composite_fragment);
	glBindAttribLocation(state.bloom_composite_program, 0, "position");
	glBindAttribLocation(state.bloom_composite_program, 1, "texture_coord");
	glLinkProgram(state.bloom_composite_program);
	glDeleteShader(bloom_composite_vertex);
	glDeleteShader(bloom_composite_fragment);

	glUseProgram(state.bloom_composite_program);
	state.composite_uniform_bloom_strength = glGetUniformLocation(state.bloom_composite_program, "bloom_strength");
	state.composite_uniform_crt_sampler = glGetUniformLocation(state.bloom_composite_program, "crt_texture");
	state.composite_uniform_bloom_sampler = glGetUniformLocation(state.bloom_composite_program, "bloom_texture");

	// Initialize bloom parameters
	state.bloom_threshold = 0.8f;  // Lower threshold = more pixels bloom
	state.bloom_strength = 0.5f;   // Higher strength = brighter bloom
	state.persistence_decay = 0.02f;  // 0.5 = subtle, 0.7 = more noticeable

	glGenVertexArrays(1, &state.vao);
	glGenBuffers(1, &state.vbo);
	glGenBuffers(1, &state.ebo);
	glBindVertexArray(state.vao);
	const float vertices[] = {
		-1.0f, -1.0f, 0.0f, 0.0f,
		 1.0f, -1.0f, 1.0f, 0.0f,
		 1.0f,  1.0f, 1.0f, 1.0f,
		-1.0f,  1.0f, 0.0f, 1.0f
	};
	static const unsigned int indices[] = { 0, 1, 2, 2, 3, 0 };
	glBindBuffer(GL_ARRAY_BUFFER, state.vbo);
	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, state.ebo);
	glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);
	glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(float), (void*)0);
	glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(float), (void*)(2 * sizeof(float)));
	glEnableVertexAttribArray(0);
	glEnableVertexAttribArray(1);
	glBindVertexArray(0);
}

// [=]===^=[ render_frame ]=================================================================^===[=]
__attribute__((always_inline))
static inline void render_frame(void) {
	// Check if viewport changed and we need to recreate render targets
	if(state.viewport_changed) {
		setup_render_targets();
		state.viewport_changed = 0;
	}

	// Upload new frame to texture
	glActiveTexture(GL_TEXTURE0);
	glBindTexture(GL_TEXTURE_2D, state.texture);
	glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, state.render_width, state.render_height, GL_RGBA, GL_UNSIGNED_INT_8_8_8_8, display_buffer);

	// Apply phosphor persistence (subtle trails on bright objects)
	// Render: state.texture (current upload) + persistence_texture (previous) -> persistence_output_texture
	glBindFramebuffer(GL_FRAMEBUFFER, state.persistence_fbo);
	glViewport(0, 0, state.render_width, state.render_height);

	glUseProgram(state.persistence_program);
	glActiveTexture(GL_TEXTURE0);
	glBindTexture(GL_TEXTURE_2D, state.texture);  // Current frame just uploaded
	glActiveTexture(GL_TEXTURE1);
	glBindTexture(GL_TEXTURE_2D, state.persistence_texture);  // Previous frame
	glUniform1i(glGetUniformLocation(state.persistence_program, "current_frame"), 0);
	glUniform1i(glGetUniformLocation(state.persistence_program, "previous_frame"), 1);
	glUniform1f(glGetUniformLocation(state.persistence_program, "decay"), state.persistence_decay);

	glBindVertexArray(state.vao);
	glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);

	// Copy output back to persistence_texture for next frame
	glBindTexture(GL_TEXTURE_2D, state.persistence_texture);
	glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 0, 0, state.render_width, state.render_height);

	// Use persistence output as source for rest of rendering pipeline
	GLuint source_texture = state.persistence_output_texture;

	if(state.toggle_bloom) {
		// ========== PASS 1: Upscale + Warp source (matches CRT geometry) ==========
		glBindFramebuffer(GL_FRAMEBUFFER, state.upscaled_source_fbo);
		glViewport(0, 0, state.viewport.w, state.viewport.h);
		glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
		glClear(GL_COLOR_BUFFER_BIT);

		glUseProgram(state.upscale_warp_program);
		glActiveTexture(GL_TEXTURE0);
		glBindTexture(GL_TEXTURE_2D, source_texture);
		// Use linear filtering for upscale+warp to reduce aliasing in bloom
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
		glUniform1i(glGetUniformLocation(state.upscale_warp_program, "source"), 0);
		glUniform2f(glGetUniformLocation(state.upscale_warp_program, "resolution"), (float)state.viewport.w, (float)state.viewport.h);
		glUniform2f(glGetUniformLocation(state.upscale_warp_program, "src_image_size"), (float)state.render_width, (float)state.render_height);

		glBindVertexArray(state.vao);
		glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);

		// Restore nearest filtering for CRT shader
		glBindTexture(GL_TEXTURE_2D, source_texture);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

		// ========== PASS 2: Extract bright pixels from upscaled source ==========
		glBindFramebuffer(GL_FRAMEBUFFER, state.bloom_temp_fbo);
		glViewport(0, 0, state.bloom_width, state.bloom_height);
		glClear(GL_COLOR_BUFFER_BIT);

		glUseProgram(state.bloom_extract_program);
		glActiveTexture(GL_TEXTURE0);
		glBindTexture(GL_TEXTURE_2D, state.upscaled_source_texture);
		glUniform1f(state.bloom_uniform_threshold, state.bloom_threshold);
		glUniform1i(state.bloom_uniform_sampler, 0);

		glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);

		// ========== PASS 3: Horizontal blur ==========
		glBindFramebuffer(GL_FRAMEBUFFER, state.bloom_fbo);
		glViewport(0, 0, state.bloom_width, state.bloom_height);
		glClear(GL_COLOR_BUFFER_BIT);

		glUseProgram(state.bloom_blur_program);
		glActiveTexture(GL_TEXTURE0);
		glBindTexture(GL_TEXTURE_2D, state.bloom_temp_texture);
		glUniform1i(state.blur_uniform_horizontal, 1);
		glUniform1i(state.blur_uniform_sampler, 0);

		glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);

		// ========== PASS 4: Vertical blur ==========
		glBindFramebuffer(GL_FRAMEBUFFER, state.bloom_temp_fbo);
		glViewport(0, 0, state.bloom_width, state.bloom_height);
		glClear(GL_COLOR_BUFFER_BIT);

		glUseProgram(state.bloom_blur_program);
		glActiveTexture(GL_TEXTURE0);
		glBindTexture(GL_TEXTURE_2D, state.bloom_texture);
		glUniform1i(state.blur_uniform_horizontal, 0);
		glUniform1i(state.blur_uniform_sampler, 0);

		glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);

		// ========== PASS 5: CRT Shader to offscreen FBO ==========
		glBindFramebuffer(GL_FRAMEBUFFER, state.crt_fbo);
		glViewport(0, 0, state.viewport.w, state.viewport.h);
		glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
		glClear(GL_COLOR_BUFFER_BIT);

		glUseProgram(state.shader_program);
		glActiveTexture(GL_TEXTURE0);
		glBindTexture(GL_TEXTURE_2D, source_texture);
		glUniform2f(state.uniform_src_image_size, (float)state.render_width, (float)state.render_height);
		glUniform2f(state.uniform_resolution, (float)state.viewport.w, (float)state.viewport.h);
		glUniform1f(state.uniform_brightness, state.brightness);
		glUniform4f(state.uniform_tone, state.tone_data[0], state.tone_data[1], state.tone_data[2], state.tone_data[3]);
		glUniform1i(state.uniform_crt_emulation, state.toggle_crt_emulation);
		glUniform1i(state.uniform_apply_mask, 0);  // Don't apply mask - composite will do it
		glUniform1i(state.uniform_sampler_location, 0);

		glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);

		// ========== PASS 6: Composite CRT + Bloom to screen ==========
		glBindFramebuffer(GL_FRAMEBUFFER, 0);
		glViewport(state.viewport.x, state.viewport.y, state.viewport.w, state.viewport.h);
		glClear(GL_COLOR_BUFFER_BIT);

		glUseProgram(state.bloom_composite_program);
		glActiveTexture(GL_TEXTURE0);
		glBindTexture(GL_TEXTURE_2D, state.crt_output_texture);
		glActiveTexture(GL_TEXTURE1);
		glBindTexture(GL_TEXTURE_2D, state.bloom_temp_texture);
		glUniform1f(state.composite_uniform_bloom_strength, state.bloom_strength);
		glUniform1i(state.composite_uniform_crt_sampler, 0);
		glUniform1i(state.composite_uniform_bloom_sampler, 1);
		glUniform2f(glGetUniformLocation(state.bloom_composite_program, "bloom_size"), (float)state.bloom_width, (float)state.bloom_height);
		glUniform2f(glGetUniformLocation(state.bloom_composite_program, "src_image_size"), (float)state.render_width, (float)state.render_height);
		glUniform2f(glGetUniformLocation(state.bloom_composite_program, "viewport_size"), (float)state.viewport.w, (float)state.viewport.h);

		glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);

		glBindVertexArray(0);
		glUseProgram(0);

	} else {
		// ========== Single pass: CRT Shader directly to screen ==========
		glBindFramebuffer(GL_FRAMEBUFFER, 0);
		glViewport(state.viewport.x, state.viewport.y, state.viewport.w, state.viewport.h);
		glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
		glClear(GL_COLOR_BUFFER_BIT);

		glUseProgram(state.shader_program);
		glActiveTexture(GL_TEXTURE0);
		glBindTexture(GL_TEXTURE_2D, source_texture);
		glUniform2f(state.uniform_src_image_size, (float)state.render_width, (float)state.render_height);
		glUniform2f(state.uniform_resolution, (float)state.viewport.w, (float)state.viewport.h);
		glUniform1f(state.uniform_brightness, state.brightness);
		glUniform4f(state.uniform_tone, state.tone_data[0], state.tone_data[1], state.tone_data[2], state.tone_data[3]);
		glUniform1i(state.uniform_crt_emulation, state.toggle_crt_emulation);
		glUniform1i(state.uniform_apply_mask, 1);  // Apply mask in CRT shader when bloom disabled
		glUniform1i(state.uniform_sampler_location, 0);

		glBindVertexArray(state.vao);
		glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);

		glBindVertexArray(0);
		glUseProgram(0);
	}
}