Subversion Repositories Games.Carmageddon

#include "gl_renderer.h"

#include "brender/brender.h"

#include "harness.h"

#include "harness/trace.h"

#include "resources/3d_frag.glsl.h"

#include "resources/3d_vert.glsl.h"

#include "resources/framebuffer_frag.glsl.h"

#include "resources/framebuffer_vert.glsl.h"

#include "stored_context.h"

#include <glad/glad.h>

#include <stdio.h>

#include <string.h>

static GLuint screen_buffer_vao, screen_buffer_ebo;

static GLuint fullscreen_quad_texture, palette_texture, depth_texture;

static GLuint shader_program_2d;

static GLuint shader_program_3d;

static GLuint framebuffer_id, framebuffer_texture = 0;

// holds the latest uploaded version of the colour_buffer. Available in shader for blending

static GLuint current_colourbuffer_texture;

static uint8_t gl_palette[4 * 256]; // RGBA

static uint8_t* screen_buffer_flip_pixels;

static uint16_t* depth_buffer_flip_pixels;

static int render_width, render_height;

static int vp_x, vp_y, vp_width, vp_height;

static br_pixelmap *last_colour_buffer, *last_depth_buffer;

static int dirty_buffers = 0;

static tStored_material* current_material;

static br_pixelmap* current_shade_table;

static br_matrix4 view_matrix;

// Increment flush_counter during flush, and upload_counter when we upload the colour_buffer texture.

// If the counters are equal, we can avoid re-uploading the same thing.

static unsigned int flush_counter = 0, colourbuffer_upload_counter = 0;

typedef struct gl_vertex {

    br_vector3 p;

    br_vector2 map;

    br_vector3 n;

    float colour_index; // float to allow interpolation

} gl_vertex;

struct {

    GLuint model, view, projection;

    // gl_NormalMatrix replacement

    GLuint normal_matrix;

    GLuint clip_plane_count;

    GLuint clip_planes[6];

    GLuint colour_buffer_texture;

    GLuint viewport_height;

    GLuint material_flags;

    GLuint material_texture_enabled;

    GLuint material_texture_pixelmap;

    GLuint material_uv_transform;

    GLuint material_shade_table;

    GLuint material_blend_enabled;

    GLuint material_blend_table;

    GLuint material_index_base;

    // GLuint material_index_range;  TODO: re-add when we add untextured lighting

    GLuint material_shade_table_height;

} uniforms_3d;

struct {

    GLuint pixels, palette;

} uniforms_2d;

static GLuint CreateShaderProgram(char* name, const char* vertex_shader, const int vertex_shader_len, const char* fragment_shader, const int fragment_shader_len) {

    int success;

    char log_buffer[1024];

    GLuint program;

    GLuint v_shader, f_shader;

    program = glCreateProgram();

    v_shader = glCreateShader(GL_VERTEX_SHADER);

    const GLchar* vertex_sources[] = { vertex_shader };

    glShaderSource(v_shader, 1, vertex_sources, &vertex_shader_len);

    glCompileShader(v_shader);

    glGetShaderiv(v_shader, GL_COMPILE_STATUS, &success);

    if (!success) {

        glGetShaderInfoLog(v_shader, 1024, NULL, log_buffer);

        LOG_PANIC("shader %s failed to compile: %s", name, log_buffer);

    }

    f_shader = glCreateShader(GL_FRAGMENT_SHADER);

    const GLchar* fragment_sources[] = { fragment_shader };

    glShaderSource(f_shader, 1, fragment_sources, &fragment_shader_len);

    glCompileShader(f_shader);

    glGetShaderiv(f_shader, GL_COMPILE_STATUS, &success);

    if (!success) {

        char log_buffer[1024];

        glGetShaderInfoLog(f_shader, 1024, NULL, log_buffer);

        LOG_PANIC("shader %s failed to compile: %s", name, log_buffer);

    }

    glAttachShader(program, v_shader);

    glAttachShader(program, f_shader);

    glLinkProgram(program);

    glDeleteShader(v_shader);

    glDeleteShader(f_shader);

    GLint link_ok = GL_FALSE;

    glGetProgramiv(program, GL_LINK_STATUS, &link_ok);

    if (!link_ok) {

        glGetShaderInfoLog(program, 1024, NULL, log_buffer);

        LOG_PANIC("shader program %s failed to link: %s", name, log_buffer);

    }

    return program;

}

static GLint GetValidatedUniformLocation(GLuint program, char* uniform_name) {

    GLint location;

    location = glGetUniformLocation(program, uniform_name);

    if (location == -1) {

        LOG_PANIC("glGetUniformLocation(%d, %s) failed. Check the shader uniform names.", program, uniform_name);

    }

    return location;

}

static void LoadShaders(void) {

    shader_program_2d = CreateShaderProgram("framebuffer", RESOURCES_FRAMEBUFFER_VERT_GLSL, sizeof(RESOURCES_FRAMEBUFFER_VERT_GLSL), RESOURCES_FRAMEBUFFER_FRAG_GLSL, sizeof(RESOURCES_FRAMEBUFFER_FRAG_GLSL));

    glUseProgram(shader_program_2d);

    uniforms_2d.pixels = GetValidatedUniformLocation(shader_program_2d, "u_pixels");

    uniforms_2d.palette = GetValidatedUniformLocation(shader_program_2d, "u_palette");

    // bind the uniform samplers to texture units:

    glUniform1i(uniforms_2d.pixels, 0);

    glUniform1i(uniforms_2d.palette, 1);

    shader_program_3d = CreateShaderProgram("3d", RESOURCES_3D_VERT_GLSL, sizeof(RESOURCES_3D_VERT_GLSL), RESOURCES_3D_FRAG_GLSL, sizeof(RESOURCES_3D_FRAG_GLSL));

    glUseProgram(shader_program_3d);

    uniforms_3d.clip_plane_count = GetValidatedUniformLocation(shader_program_3d, "u_clip_plane_count");

    for (int i = 0; i < 6; i++) {

        char name[32];

        sprintf(name, "u_clip_planes[%d]", i);

        uniforms_3d.clip_planes[i] = GetValidatedUniformLocation(shader_program_3d, name);

    }

    uniforms_3d.model = GetValidatedUniformLocation(shader_program_3d, "u_model");

    uniforms_3d.colour_buffer_texture = GetValidatedUniformLocation(shader_program_3d, "u_colour_buffer");

    uniforms_3d.projection = GetValidatedUniformLocation(shader_program_3d, "u_projection");

    uniforms_3d.view = GetValidatedUniformLocation(shader_program_3d, "u_view");

    uniforms_3d.viewport_height = GetValidatedUniformLocation(shader_program_3d, "u_viewport_height");

    uniforms_3d.normal_matrix = GetValidatedUniformLocation(shader_program_3d, "u_normal_matrix");

    uniforms_3d.material_flags = GetValidatedUniformLocation(shader_program_3d, "u_material_flags");

    uniforms_3d.material_texture_enabled = GetValidatedUniformLocation(shader_program_3d, "u_material_texture_enabled");

    uniforms_3d.material_texture_pixelmap = GetValidatedUniformLocation(shader_program_3d, "u_material_texture_pixelmap");

    uniforms_3d.material_uv_transform = GetValidatedUniformLocation(shader_program_3d, "u_material_uv_transform");

    uniforms_3d.material_shade_table = GetValidatedUniformLocation(shader_program_3d, "u_material_shade_table");

    uniforms_3d.material_shade_table_height = GetValidatedUniformLocation(shader_program_3d, "u_material_shade_table_height");

    uniforms_3d.material_blend_enabled = GetValidatedUniformLocation(shader_program_3d, "u_material_blend_enabled");

    uniforms_3d.material_blend_table = GetValidatedUniformLocation(shader_program_3d, "u_material_blend_table");

    uniforms_3d.material_index_base = GetValidatedUniformLocation(shader_program_3d, "u_material_index_base");

    // TODO: re-add when we support untextured lighting

    // uniforms_3d.material_index_range = GetValidatedUniformLocation(shader_program_3d, "u_material_index_range");

    // bind the uniform samplers to texture units

    glUniform1i(uniforms_3d.material_texture_pixelmap, 0);

    // palette occupies texture unit 1 but not required during 3d rendering

    glUniform1i(uniforms_3d.material_shade_table, 2);

    glUniform1i(uniforms_3d.material_blend_table, 3);

    glUniform1i(uniforms_3d.colour_buffer_texture, 4);

}

static void SetupFullScreenRectGeometry(void) {

    float vertices[] = {

        // positions          // colors           // texture coords

        1.0f, -1.0f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, // top right

        1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f,  // bottom right

        -1.0f, 1.0f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, // bottom left

        -1.0f, -1.0f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f // top left

    };

    unsigned int indices[] = {

        0, 1, 3, // first triangle

        1, 2, 3  // second triangle

    };

    GLuint vbo;

    glGenVertexArrays(1, &screen_buffer_vao);

    glGenBuffers(1, &vbo);

    glGenBuffers(1, &screen_buffer_ebo);

    glBindVertexArray(screen_buffer_vao);

    glBindBuffer(GL_ARRAY_BUFFER, vbo);

    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);

    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, screen_buffer_ebo);

    glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);

    // position attribute

    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);

    glEnableVertexAttribArray(0);

    // color attribute

    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(3 * sizeof(float)));

    glEnableVertexAttribArray(1);

    // texture coord attribute

    glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(6 * sizeof(float)));

    glEnableVertexAttribArray(2);

    glBindVertexArray(0);

}

void GLRenderer_Init(int pRender_width, int pRender_height) {

    render_width = pRender_width;

    render_height = pRender_height;

    LOG_INFO("OpenGL vendor string: %s", glGetString(GL_VENDOR));

    LOG_INFO("OpenGL renderer string: %s", glGetString(GL_RENDERER));

    LOG_INFO("OpenGL version string: %s", glGetString(GL_VERSION));

    LOG_INFO("OpenGL shading language version string: %s", glGetString(GL_SHADING_LANGUAGE_VERSION));

    if (glGetString(GL_SHADING_LANGUAGE_VERSION) == NULL) {

        LOG_PANIC("GL_SHADING_LANGUAGE_VERSION is null");

    }

    LoadShaders();

    SetupFullScreenRectGeometry();

    // config

    glDisable(GL_BLEND);

    glDepthFunc(GL_LESS);

    glClearColor(0, 0, 0, 1.0f);

    glClear(GL_COLOR_BUFFER_BIT);

    glEnable(GL_CULL_FACE);

    glCullFace(GL_BACK);

    // textures

    glGenTextures(1, &fullscreen_quad_texture);

    glGenTextures(1, &palette_texture);

    glGenTextures(1, &framebuffer_texture);

    glGenTextures(1, &depth_texture);

    glGenTextures(1, &current_colourbuffer_texture);

    // setup framebuffer

    glGenFramebuffers(1, &framebuffer_id);

    glBindFramebuffer(GL_FRAMEBUFFER, framebuffer_id);

    // set pixel storage alignment to 1 byte

    glPixelStorei(GL_PACK_ALIGNMENT, 1);

    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);

    glBindTexture(GL_TEXTURE_2D, fullscreen_quad_texture);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

    glBindTexture(GL_TEXTURE_2D, palette_texture);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

    glBindTexture(GL_TEXTURE_2D, framebuffer_texture);

    glTexImage2D(GL_TEXTURE_2D, 0, GL_R8UI, render_width, render_height, 0, GL_RED_INTEGER, GL_UNSIGNED_BYTE, NULL);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, framebuffer_texture, 0);

    glBindTexture(GL_TEXTURE_2D, current_colourbuffer_texture);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

    glBindTexture(GL_TEXTURE_2D, depth_texture);

    glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT16, render_width, render_height, 0, GL_DEPTH_COMPONENT, GL_UNSIGNED_SHORT, 0);

    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, depth_texture, 0);

    if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {

        LOG_PANIC("Framebuffer is not complete!");

    }

    glBindFramebuffer(GL_FRAMEBUFFER, 0);

    screen_buffer_flip_pixels = malloc(sizeof(uint8_t) * render_width * render_height);

    depth_buffer_flip_pixels = malloc(sizeof(uint16_t) * render_width * render_height);

    CHECK_GL_ERROR("initializeOpenGLContext");

}

void GLRenderer_SetPalette(uint8_t* rgba_colors) {

    for (int i = 0; i < 256; i++) {

        gl_palette[i * 4] = rgba_colors[i * 4 + 2];

        gl_palette[i * 4 + 1] = rgba_colors[i * 4 + 1];

        gl_palette[i * 4 + 2] = rgba_colors[i * 4];

        // palette index 0 is transparent, so set alpha to 0

        if (i == 0) {

            gl_palette[i * 4 + 3] = 0;

        } else {

            gl_palette[i * 4 + 3] = 0xff;

        }

    }

    glActiveTexture(GL_TEXTURE1);

    glBindTexture(GL_TEXTURE_2D, palette_texture);

    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, 256, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE, gl_palette);

    // reset active texture back to default

    glActiveTexture(GL_TEXTURE0);

    CHECK_GL_ERROR("GLRenderer_SetPalette");

}

void GLRenderer_SetShadeTable(br_pixelmap* table) {

    if (current_shade_table == table) {

        return;

    }

    // shade table uses texture unit 2

    glActiveTexture(GL_TEXTURE2);

    tStored_pixelmap* stored = table->stored;

    glBindTexture(GL_TEXTURE_2D, stored->id);

    // reset active texture back to default

    glActiveTexture(GL_TEXTURE0);

    current_shade_table = table;

}

void GLRenderer_SetBlendTable(br_pixelmap* table) {

    if (flush_counter != colourbuffer_upload_counter) {

        GLRenderer_FlushBuffer(eFlush_color_buffer);

        glActiveTexture(GL_TEXTURE4);

        glBindTexture(GL_TEXTURE_2D, current_colourbuffer_texture);

        glTexImage2D(GL_TEXTURE_2D, 0, GL_R8UI, render_width, render_height, 0, GL_RED_INTEGER, GL_UNSIGNED_BYTE, last_colour_buffer->pixels);

        colourbuffer_upload_counter = flush_counter;

    }

    // blend table uses texture unit 3

    glActiveTexture(GL_TEXTURE3);

    tStored_pixelmap* stored = table->stored;

    glBindTexture(GL_TEXTURE_2D, stored->id);

    // reset active texture back to default

    glActiveTexture(GL_TEXTURE0);

}

extern br_v1db_state v1db;

void GLRenderer_BeginScene(br_actor* camera, br_pixelmap* colour_buffer, br_pixelmap* depth_buffer) {

    last_colour_buffer = colour_buffer;

    last_depth_buffer = depth_buffer;

    glViewport(colour_buffer->base_x, render_height - colour_buffer->height - colour_buffer->base_y, colour_buffer->width, colour_buffer->height);

    glUseProgram(shader_program_3d);

    glUniform1ui(uniforms_3d.viewport_height, render_height);

    br_camera* cam = camera->type_data;

    current_material = NULL;

    current_shade_table = NULL;

    // clip planes

    int enabled_clip_planes = 0;

    for (int i = 0; i < v1db.enabled_clip_planes.max; i++) {

        if (v1db.enabled_clip_planes.enabled == NULL || !v1db.enabled_clip_planes.enabled[i]) {

            continue;

        }

        br_vector4* v4 = v1db.enabled_clip_planes.enabled[i]->type_data;

        glUniform4f(uniforms_3d.clip_planes[enabled_clip_planes], v4->v[0], v4->v[1], v4->v[2], v4->v[3]);

        enabled_clip_planes++;

    }

    glUniform1i(uniforms_3d.clip_plane_count, enabled_clip_planes);

    // view matrix

    BrMatrix4Copy34(&view_matrix, &v1db.camera_path[0].m);

    BrMatrix4Inverse(&view_matrix, &view_matrix);

    glUniformMatrix4fv(uniforms_3d.view, 1, GL_FALSE, &view_matrix.m[0][0]);

    // projection matrix

    br_matrix4 projection;

    BrMatrix4Perspective(&projection, cam->field_of_view, cam->aspect, cam->hither_z, cam->yon_z);

    // hack: not sure why we have to do this, but this makes the result the same as `glm_perspective`

    projection.m[2][2] *= -1;

    glUniformMatrix4fv(uniforms_3d.projection, 1, GL_FALSE, &projection.m[0][0]);

    glBindFramebuffer(GL_FRAMEBUFFER, framebuffer_id);

}

void GLRenderer_EndScene(void) {

    //  switch back to default fb and reset state

    glBindFramebuffer(GL_FRAMEBUFFER, 0);

    glDepthMask(GL_TRUE);

    glDepthMask(GL_TRUE);

    CHECK_GL_ERROR("GLRenderer_EndScene");

}

void GLRenderer_FullScreenQuad(uint8_t* screen_buffer) {

    glViewport(vp_x, vp_y, vp_width, vp_height);

    glBindFramebuffer(GL_FRAMEBUFFER, 0);

    glDisable(GL_DEPTH_TEST);

    glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);

    glBindTexture(GL_TEXTURE_2D, fullscreen_quad_texture);

    glTexImage2D(GL_TEXTURE_2D, 0, GL_R8UI, render_width, render_height, 0, GL_RED_INTEGER, GL_UNSIGNED_BYTE, screen_buffer);

    glBindVertexArray(screen_buffer_vao);

    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, screen_buffer_ebo);

    glUseProgram(shader_program_2d);

    glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);

    glBindVertexArray(0);

    glEnable(GL_DEPTH_TEST);

    CHECK_GL_ERROR("GLRenderer_RenderFullScreenQuad");

}

void GLRenderer_ClearBuffers(void) {

    // clear our virtual framebuffer

    glBindFramebuffer(GL_FRAMEBUFFER, framebuffer_id);

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    // clear real framebuffer

    glBindFramebuffer(GL_FRAMEBUFFER, 0);

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    CHECK_GL_ERROR("GLRenderer_ClearBuffers");

}

void GLRenderer_BufferModel(br_model* model) {

    tStored_model_context* ctx;

    v11model* v11;

    if (model->stored != NULL) {

        LOG_PANIC("trying to build a stored model");

    }

    v11 = model->prepared;

    ctx = NewStoredModelContext();

    int total_verts = 0, total_faces = 0;

    for (int i = 0; i < v11->ngroups; i++) {

        total_verts += v11->groups[i].nvertices;

        total_faces += v11->groups[i].nfaces;

    }

    // override normals

    br_vector3 v3 = { { 0, 0, 0 } };

    for (int g = 0; g < v11->ngroups; g++) {

        for (int i = 0; i < v11->groups[g].nvertices; i++) {

            v11->groups[g].vertices[i].n = v3;

        }

    }

    br_vector3 v0v1, v2v1, normal;

    for (int g = 0; g < v11->ngroups; g++) {

        v11group* group = &v11->groups[g];

        for (int i = 0; i < group->nfaces; i++) {

            v11face* f = &group->faces[i];

            fmt_vertex* v0 = &group->vertices[f->vertices[0]];

            fmt_vertex* v1 = &group->vertices[f->vertices[1]];

            fmt_vertex* v2 = &group->vertices[f->vertices[2]];

            BrVector3Sub(&v0v1, &v0->p, &v1->p);

            BrVector3Sub(&v2v1, &v2->p, &v1->p);

            BrVector3Cross(&normal, &v0v1, &v2v1);

            BrVector3Accumulate(&v0->n, &normal);

            BrVector3Accumulate(&v1->n, &normal);

            BrVector3Accumulate(&v2->n, &normal);

        }

    }

    for (int g = 0; g < v11->ngroups; g++) {

        for (int i = 0; i < v11->groups[g].nvertices; i++) {

            BrVector3Normalise(&v11->groups[g].vertices[i].n, &v11->groups[g].vertices[i].n);

        }

    }

    gl_vertex* verts = malloc(sizeof(gl_vertex) * total_verts);

    unsigned int* indices = malloc(sizeof(int) * 3 * total_faces);

    int v_index = 0;

    int i_index = 0;

    int face_offset = 0;

    for (int g = 0; g < v11->ngroups; g++) {

        for (int i = 0; i < v11->groups[g].nvertices; i++) {

            fmt_vertex* v = &v11->groups[g].vertices[i];

            verts[v_index].p = v->p;

            verts[v_index].n = v->n;

            verts[v_index].map = v->map;

            verts[v_index].colour_index = BR_ALPHA(v11->groups[g].vertex_colours[i]);

            v_index++;

        }

        for (int i = 0; i < v11->groups[g].nfaces; i++) {

            v11face* f = &v11->groups[g].faces[i];

            indices[i_index++] = f->vertices[0] + face_offset;

            indices[i_index++] = f->vertices[1] + face_offset;

            indices[i_index++] = f->vertices[2] + face_offset;

        }

        face_offset += v11->groups[g].nvertices;

    }

    glGenVertexArrays(1, &ctx->vao_id);

    glGenBuffers(1, &ctx->vbo_id);

    glGenBuffers(1, &ctx->ebo_id);

    // Vertices

    glBindVertexArray(ctx->vao_id);

    glBindBuffer(GL_ARRAY_BUFFER, ctx->vbo_id);

    glBufferData(GL_ARRAY_BUFFER, sizeof(gl_vertex) * total_verts, verts, GL_STATIC_DRAW);

    // pos

    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(gl_vertex), (void*)offsetof(gl_vertex, p));

    glEnableVertexAttribArray(0);

    // normal

    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(gl_vertex), (void*)offsetof(gl_vertex, n));

    glEnableVertexAttribArray(1);

    // uv coordinates

    glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, sizeof(gl_vertex), (void*)offsetof(gl_vertex, map));

    glEnableVertexAttribArray(2);

    // color

    glVertexAttribPointer(3, 1, GL_FLOAT, GL_FALSE, sizeof(gl_vertex), (void*)offsetof(gl_vertex, colour_index));

    glEnableVertexAttribArray(3);

    // Indices

    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ctx->ebo_id);

    glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(int) * 3 * total_faces, indices, GL_STATIC_DRAW);

    glBindVertexArray(0);

    free(verts);

    free(indices);

    model->stored = ctx;

    CHECK_GL_ERROR("after build model");

}

void setActiveMaterial(tStored_material* material) {

    if (material == NULL || material == current_material) {

        return;

    }

    glUniformMatrix2x3fv(uniforms_3d.material_uv_transform, 1, GL_TRUE, &material->map_transform.m[0][0]);

    if (material->pixelmap) {

        tStored_pixelmap* stored_px = material->pixelmap->stored;

        if (stored_px == NULL) {

            LOG_PANIC("stored_px is null for pixelmap %s", material->pixelmap->identifier);

        }

        glBindTexture(GL_TEXTURE_2D, stored_px->id);

        glUniform1ui(uniforms_3d.material_texture_enabled, 1);

    } else {

        glUniform1ui(uniforms_3d.material_texture_enabled, 0);

        // index_base and index_range are only used for untextured materials

        glUniform1ui(uniforms_3d.material_index_base, material->index_base);

        // glUniform1ui(uniforms_3d.material_index_range, material->index_range);  TODO: re-add when we support untextured lighting

    }

    if (material->shade_table) {

        glUniform1ui(uniforms_3d.material_shade_table_height, material->shade_table->height);

        GLRenderer_SetShadeTable(material->shade_table);

    }

    if (material->index_blend) {

        glUniform1ui(uniforms_3d.material_blend_enabled, 1);

        GLRenderer_SetBlendTable(material->index_blend);

        // materials with index_blend do not write to depth buffer (https://www.cwaboard.co.uk/viewtopic.php?p=105846&sid=58ad8910238000ca14b01dad85117175#p105846)

        glDepthMask(GL_FALSE);

    } else {

        glUniform1ui(uniforms_3d.material_blend_enabled, 0);

        glDepthMask(GL_TRUE);

    }

    glUniform1ui(uniforms_3d.material_flags, material->flags);

    if (material->flags & (BR_MATF_TWO_SIDED | BR_MATF_ALWAYS_VISIBLE)) {

        glDisable(GL_CULL_FACE);

    } else {

        glEnable(GL_CULL_FACE);

    }

    CHECK_GL_ERROR("GLRenderer_RenderModelxx");

}

void GLRenderer_Model(br_actor* actor, br_model* model, br_material* material, br_token render_type, br_matrix34 model_matrix) {

    tStored_model_context* ctx;

    v11group* group;

    int element_index = 0;

    if (model->flags & BR_MODF_DETHRACE_FORCE_BUFFER_UPDATE) {

        if (model->stored) {

            ((br_object*)model->stored)->dispatch->_free((br_object*)model->stored);

            model->stored = NULL;

        }

        GLRenderer_BufferModel(model);

        model->flags &= ~BR_MODF_DETHRACE_FORCE_BUFFER_UPDATE;

    }

    ctx = model->stored;

    v11model* v11 = model->prepared;

    if (v11 == NULL) {

        // LOG_WARN("No model prepared for %s", model->identifier);

        return;

    }

    // model matrix

    br_matrix4 view_model_matrix, model_matrix4, inverse, inverse_transpose;

    BrMatrix4Copy34(&model_matrix4, &model_matrix);

    glUniformMatrix4fv(uniforms_3d.model, 1, GL_FALSE, model_matrix4.m[0]);

    // normal matrix (http://www.lighthouse3d.com/tutorials/glsl-12-tutorial/the-normal-matrix/)

    BrMatrix4Mul(&view_model_matrix, &view_matrix, &model_matrix4);

    BrMatrix4Inverse(&inverse, &view_model_matrix);

    // transpose

    for (int i = 0; i < 4; i++) {

        for (int j = 0; j < 4; j++) {

            inverse_transpose.m[i][j] = inverse.m[j][i];

        }

    }

    glUniformMatrix4fv(uniforms_3d.normal_matrix, 1, GL_FALSE, &inverse_transpose.m[0][0]);

    glBindVertexArray(ctx->vao_id);

    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ctx->ebo_id);

    // set default material for this actor/model

    setActiveMaterial(material->stored);

    switch (render_type) {

    case BRT_TRIANGLE:

        glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);

        break;

    case BRT_LINE:

        glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);

        glUniform1ui(uniforms_3d.material_index_base, 255);

        glUniform1ui(uniforms_3d.material_flags, 0);

        break;

    default:

        LOG_PANIC("render_type %d is not supported?!", render_type);

    }

    for (int g = 0; g < v11->ngroups; g++) {

        group = &v11->groups[g];

        setActiveMaterial(group->stored);

        glDrawElements(GL_TRIANGLES, group->nfaces * 3, GL_UNSIGNED_INT, (void*)(element_index * sizeof(int)));

        element_index += group->nfaces * 3;

    }

    glBindVertexArray(0);

    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);

    dirty_buffers = 1;

    CHECK_GL_ERROR("GLRenderer_RenderModel");

}

void GLRenderer_BufferMaterial(br_material* mat) {

    tStored_material* stored = mat->stored;

    if (!stored) {

        stored = NewStoredMaterial();

        mat->stored = stored;

        if (mat->identifier) {

            strcpy(stored->identifier, mat->identifier);

        }

    }

    BrMatrix23Copy(&stored->map_transform, &mat->map_transform);

    stored->pixelmap = mat->colour_map;

    stored->flags = mat->flags;

    stored->shade_table = mat->index_shade;

    stored->index_base = mat->index_base;

    stored->index_range = mat->index_range;

    stored->index_blend = mat->index_blend;

}

void GLRenderer_BufferTexture(br_pixelmap* pm) {

    tStored_pixelmap* stored = pm->stored;

    if (pm->stored) {

    } else {

        stored = NewStoredPixelmap();

        glGenTextures(1, &stored->id);

        pm->stored = stored;

    }

    // sometimes the pixelmap has row_bytes > width. OpenGL expects linear pixels, so flatten it out

    uint8_t* linear_pixels = malloc(sizeof(uint8_t) * pm->width * pm->height);

    uint8_t* original_pixels = pm->pixels;

    for (int y = 0; y < pm->height; y++) {

        for (int x = 0; x < pm->width; x++) {

            linear_pixels[y * pm->width + x] = original_pixels[y * pm->row_bytes + x];

        }

    }

    glBindTexture(GL_TEXTURE_2D, stored->id);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

    glTexImage2D(GL_TEXTURE_2D, 0, GL_R8UI, pm->width, pm->height, 0, GL_RED_INTEGER, GL_UNSIGNED_BYTE, linear_pixels);

    free(linear_pixels);

    CHECK_GL_ERROR("GLRenderer_BufferTexture");

}

void GLRenderer_FlushBuffer(tRenderer_flush_type flush_type) {

    if (!dirty_buffers) {

        return;

    }

    // pull framebuffer into cpu memory to emulate BRender behavior

    glBindTexture(GL_TEXTURE_2D, framebuffer_texture);

    glGetTexImage(GL_TEXTURE_2D, 0, GL_RED_INTEGER, GL_UNSIGNED_BYTE, screen_buffer_flip_pixels);

    // flip texture to match the expected orientation

    int dest_y = render_height;

    uint8_t* pm_pixels = last_colour_buffer->pixels;

    uint8_t new_pixel;