r_draw.cpp

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/*
Copyright (C) 1997-2001 Id Software, Inc.

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

*/

#include "r_local.h"
#include "r_sphere.h"
#include "r_error.h"
#include "r_draw.h"
#include "r_mesh.h"
#include "r_framebuffer.h"
#include "r_program.h"
#include "r_misc.h"
#include "../cl_console.h"

image_t* shadow;

/* console font */
static image_t* draw_chars;

#define MAX_CHARS 8192

typedef struct char_arrays_s {
    GLfloat texcoords[MAX_CHARS * 4 * 2];
    int texcoord_index;

    GLshort verts[MAX_CHARS * 4 * 2];
    int vert_index;

    GLbyte colors[MAX_CHARS * 4 * 4];
    int color_index;
} char_arrays_t;

static char_arrays_t r_char_arrays;

#define MAX_BATCH_ENTRIES 512

typedef struct batch_arrays_s {
    GLshort verts[MAX_BATCH_ENTRIES * 4 * 2];
    int vert_index;

    GLbyte colors[MAX_BATCH_ENTRIES * 4 * 4];
    int color_index;
} batch_arrays_t;

static batch_arrays_t r_fill_arrays;

#define MAX_BBOX_ENTRIES 256

typedef struct bbox_arrays_s {
    float bboxes[3 * 8 * MAX_BBOX_ENTRIES];
    int bboxes_index;
} bbox_arrays_t;

static bbox_arrays_t r_bbox_array;

void R_DrawInitLocal (void)
{
    shadow = R_FindImage("pics/sfx/shadow", it_effect);
    if (shadow == r_noTexture)
        Com_Printf("Could not find shadow image in game pics/sfx directory!\n");

    draw_chars = R_FindImage("pics/conchars", it_chars);
    if (draw_chars == r_noTexture)
        Com_Error(ERR_FATAL, "Could not find conchars image in game pics directory!");
}

void R_DrawChar (int x, int y, int num, uint32_t color)
{
    num &= 255;

    if ((num & 127) == ' ')     /* space */
        return;

    if (y <= -con_fontHeight)
        return;                 /* totally off screen */

    if (r_char_arrays.vert_index >= lengthof(r_char_arrays.verts))
        return;

    int row = (int) num >> 4;
    int col = (int) num & 15;

    /* 0.0625 => 16 cols (conchars images) */
    float frow = row * 0.0625;
    float fcol = col * 0.0625;

    memcpy(&r_char_arrays.colors[r_char_arrays.color_index +  0], &color, 4);
    memcpy(&r_char_arrays.colors[r_char_arrays.color_index +  4], &color, 4);
    memcpy(&r_char_arrays.colors[r_char_arrays.color_index +  8], &color, 4);
    memcpy(&r_char_arrays.colors[r_char_arrays.color_index + 12], &color, 4);

    r_char_arrays.color_index += 16;

    r_char_arrays.texcoords[r_char_arrays.texcoord_index + 0] = fcol;
    r_char_arrays.texcoords[r_char_arrays.texcoord_index + 1] = frow;

    r_char_arrays.texcoords[r_char_arrays.texcoord_index + 2] = fcol + 0.0625;
    r_char_arrays.texcoords[r_char_arrays.texcoord_index + 3] = frow;

    r_char_arrays.texcoords[r_char_arrays.texcoord_index + 4] = fcol + 0.0625;
    r_char_arrays.texcoords[r_char_arrays.texcoord_index + 5] = frow + 0.0625;

    r_char_arrays.texcoords[r_char_arrays.texcoord_index + 6] = fcol;
    r_char_arrays.texcoords[r_char_arrays.texcoord_index + 7] = frow + 0.0625;

    r_char_arrays.texcoord_index += 8;

    r_char_arrays.verts[r_char_arrays.vert_index + 0] = x;
    r_char_arrays.verts[r_char_arrays.vert_index + 1] = y;

    r_char_arrays.verts[r_char_arrays.vert_index + 2] = x + con_fontWidth;
    r_char_arrays.verts[r_char_arrays.vert_index + 3] = y;

    r_char_arrays.verts[r_char_arrays.vert_index + 4] = x + con_fontWidth;
    r_char_arrays.verts[r_char_arrays.vert_index + 5] = y + con_fontHeight;

    r_char_arrays.verts[r_char_arrays.vert_index + 6] = x;
    r_char_arrays.verts[r_char_arrays.vert_index + 7] = y + con_fontHeight;

    r_char_arrays.vert_index += 8;
}

void R_DrawChars (void)
{
    if (!r_char_arrays.vert_index)
        return;

    R_BindTexture(draw_chars->texnum);

    R_EnableColorArray(true);

    /* alter the array pointers */
    R_BindArray(GL_COLOR_ARRAY, GL_UNSIGNED_BYTE, r_char_arrays.colors);
    R_BindArray(GL_TEXTURE_COORD_ARRAY, GL_FLOAT, r_char_arrays.texcoords);
    glVertexPointer(2, GL_SHORT, 0, r_char_arrays.verts);

    R_DrawArrays(0, r_char_arrays.vert_index / 2);

    refdef.batchCount++;

    r_char_arrays.color_index = 0;
    r_char_arrays.texcoord_index = 0;
    r_char_arrays.vert_index = 0;

    /* and restore them */
    R_BindDefaultArray(GL_TEXTURE_COORD_ARRAY);
    R_BindDefaultArray(GL_VERTEX_ARRAY);
    R_BindDefaultArray(GL_COLOR_ARRAY);

    R_EnableColorArray(false);
}

void R_DrawFill (int x, int y, int w, int h, const vec4_t color)
{
    const float nx = x * viddef.rx;
    const float ny = y * viddef.ry;
    const float nw = w * viddef.rx;
    const float nh = h * viddef.ry;
    const int r = color[0] * 255.0;
    const int g = color[1] * 255.0;
    const int b = color[2] * 255.0;
    const int a = color[3] * 255.0;
    const uint32_t c = LittleLong((r << 0) + (g << 8) + (b << 16) + (a << 24));

    if (r_fill_arrays.color_index >= lengthof(r_fill_arrays.colors))
        return;

    /* duplicate color data to all 4 verts */
    memcpy(&r_fill_arrays.colors[r_fill_arrays.color_index +  0], &c, 4);
    memcpy(&r_fill_arrays.colors[r_fill_arrays.color_index +  4], &c, 4);
    memcpy(&r_fill_arrays.colors[r_fill_arrays.color_index +  8], &c, 4);
    memcpy(&r_fill_arrays.colors[r_fill_arrays.color_index + 12], &c, 4);

    r_fill_arrays.color_index += 16;

    /* populate verts */
    r_fill_arrays.verts[r_fill_arrays.vert_index + 0] = nx;
    r_fill_arrays.verts[r_fill_arrays.vert_index + 1] = ny;

    r_fill_arrays.verts[r_fill_arrays.vert_index + 2] = nx + nw;
    r_fill_arrays.verts[r_fill_arrays.vert_index + 3] = ny;

    r_fill_arrays.verts[r_fill_arrays.vert_index + 4] = nx + nw;
    r_fill_arrays.verts[r_fill_arrays.vert_index + 5] = ny + nh;

    r_fill_arrays.verts[r_fill_arrays.vert_index + 6] = nx;
    r_fill_arrays.verts[r_fill_arrays.vert_index + 7] = ny + nh;

    r_fill_arrays.vert_index += 8;

    R_DrawFills();
}

void R_DrawFills (void)
{
    if (!r_fill_arrays.vert_index)
        return;

    R_EnableTexture(&texunit_diffuse, false);

    R_EnableColorArray(true);

    /* alter the array pointers */
    R_BindArray(GL_COLOR_ARRAY, GL_UNSIGNED_BYTE, r_fill_arrays.colors);
    glVertexPointer(2, GL_SHORT, 0, r_fill_arrays.verts);

    R_DrawArrays(0, r_fill_arrays.vert_index / 2);

    refdef.batchCount++;

    /* and restore them */
    R_BindDefaultArray(GL_VERTEX_ARRAY);
    R_BindDefaultArray(GL_COLOR_ARRAY);

    R_EnableColorArray(false);

    R_EnableTexture(&texunit_diffuse, true);

    r_fill_arrays.vert_index = r_fill_arrays.color_index = 0;

    R_Color(nullptr);
}

int R_UploadData (const char* name, unsigned* frame, int width, int height)
{
    image_t* img;
    unsigned* scaled;
    int scaledWidth, scaledHeight;
    int samples = r_config.gl_compressed_solid_format ? r_config.gl_compressed_solid_format : r_config.gl_solid_format;
#ifdef GL_VERSION_ES_CM_1_0
    samples = GL_RGBA;
#endif

    R_GetScaledTextureSize(width, height, &scaledWidth, &scaledHeight);

    img = R_FindImage(name, it_pic);
    if (img == r_noTexture)
        Com_Error(ERR_FATAL, "Could not find the searched image: %s", name);

    /* scan the texture for any non-255 alpha */
    for (unsigned const* i = frame, * const end = i + scaledHeight * scaledWidth; i != end; ++i) {
        if ((*i & 0xFF000000U) != 0xFF000000U) {
            samples = r_config.gl_compressed_alpha_format ? r_config.gl_compressed_alpha_format : r_config.gl_alpha_format;
            break;
        }
    }

    if (scaledWidth != width || scaledHeight != height) {  /* whereas others need to be scaled */
        scaled = Mem_PoolAllocTypeN(unsigned, scaledWidth * scaledHeight, vid_imagePool);
        R_ScaleTexture(frame, width, height, scaled, scaledWidth, scaledHeight);
    } else {
        scaled = frame;
    }

    R_BindTexture(img->texnum);
    if (img->upload_width == scaledWidth && img->upload_height == scaledHeight) {
        glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, scaledWidth, scaledHeight, GL_RGBA, GL_UNSIGNED_BYTE, scaled);
    } else {
        /* Reallocate the texture */
        img->width = width;
        img->height = height;
        img->upload_width = scaledWidth;
        img->upload_height = scaledHeight;
        glTexImage2D(GL_TEXTURE_2D, 0, samples, scaledWidth, scaledHeight, 0, GL_RGBA, GL_UNSIGNED_BYTE, scaled);
    }
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    R_CheckError();

    if (scaled != frame)
        Mem_Free(scaled);

    return img->texnum;
}

void R_DrawTexture (int texnum, int x, int y, int w, int h)
{
    const vec2_t vertexes[] = {Vector2FromInt(x, y), Vector2FromInt(x + w, y), Vector2FromInt(x + w, y + h), Vector2FromInt(x, y + h)};

    R_BindTexture(texnum);
    R_DrawImageArray(default_texcoords, vertexes, nullptr);
}

void R_DrawImage (float x, float y, const image_t* image)
{
    if (!image)
        return;

    R_DrawTexture(image->texnum, x * viddef.rx, y * viddef.ry, image->width * viddef.rx, image->height * viddef.ry);
}

void R_DrawStretchImage (float x, float y, int w, int h, const image_t* image)
{
    if (!image)
        return;

    R_DrawTexture(image->texnum, x * viddef.rx, y * viddef.ry, w * viddef.rx, h * viddef.ry);
}

const image_t* R_DrawImageArray (const vec2_t texcoords[4], const vec2_t verts[4], const image_t* image)
{
    /* alter the array pointers */
    glVertexPointer(2, GL_FLOAT, 0, verts);
    R_BindArray(GL_TEXTURE_COORD_ARRAY, GL_FLOAT, texcoords);

    if (image != nullptr)
        R_BindTexture(image->texnum);

    glDrawArrays(GL_TRIANGLE_FAN, 0, 4);

    refdef.batchCount++;

    /* and restore them */
    R_BindDefaultArray(GL_TEXTURE_COORD_ARRAY);
    R_BindDefaultArray(GL_VERTEX_ARRAY);

    return image;
}

void R_DrawRect (int x, int y, int w, int h, const vec4_t color, float lineWidth, int pattern)
{
    const float nx = x * viddef.rx;
    const float ny = y * viddef.ry;
    const float nw = w * viddef.rx;
    const float nh = h * viddef.ry;
    const vec2_t points[] = { { nx, ny }, { nx + nw, ny }, { nx + nw, ny + nh }, { nx, ny + nh } };

    R_Color(color);

    glDisable(GL_TEXTURE_2D);
    glLineWidth(lineWidth);
#ifndef GL_VERSION_ES_CM_1_0
    glLineStipple(2, pattern);
    glEnable(GL_LINE_STIPPLE);
#endif

    glVertexPointer(2, GL_FLOAT, 0, points);
    glDrawArrays(GL_LINE_LOOP, 0, 4);
    R_BindDefaultArray(GL_VERTEX_ARRAY);

    refdef.batchCount++;

    glEnable(GL_TEXTURE_2D);
    glLineWidth(1.0f);
#ifndef GL_VERSION_ES_CM_1_0
    glDisable(GL_LINE_STIPPLE);
#endif

    R_Color(nullptr);
}

void R_DrawCircle (float radius, const vec4_t color, float thickness, const vec3_t shift)
{
    vec3_t points[16];
    const size_t steps = lengthof(points);

    glEnable(GL_LINE_SMOOTH);
    glLineWidth(thickness);

    R_Color(color);

    for (unsigned int i = 0; i < steps; i++) {
        const float a = 2.0f * M_PI * (float) i / (float) steps;
        VectorSet(points[i], shift[0] + radius * cos(a), shift[1] + radius * sin(a), shift[2]);
    }

    R_BindArray(GL_VERTEX_ARRAY, GL_FLOAT, points);
    glDrawArrays(GL_LINE_LOOP, 0, steps);
    R_BindDefaultArray(GL_VERTEX_ARRAY);

    refdef.batchCount++;

    R_Color(nullptr);

    glLineWidth(1.0f);
    glDisable(GL_LINE_SMOOTH);
}

#define MAX_LINEVERTS 256

static inline void R_Draw2DArray (int points, int* verts, GLenum mode)
{
    /* fit it on screen */
    if (points > MAX_LINEVERTS * 2)
        points = MAX_LINEVERTS * 2;

    /* set vertex array pointer */
    glVertexPointer(2, GL_SHORT, 0, r_state.vertex_array_2d);

    for (int i = 0; i < points * 2; i += 2) {
        r_state.vertex_array_2d[i] = verts[i] * viddef.rx;
        r_state.vertex_array_2d[i + 1] = verts[i + 1] * viddef.ry;
    }

    glDisable(GL_TEXTURE_2D);
    glDrawArrays(mode, 0, points);
    glEnable(GL_TEXTURE_2D);
    glVertexPointer(3, GL_FLOAT, 0, r_state.vertex_array_3d);

    refdef.batchCount++;
}

void R_DrawLineStrip (int points, int* verts)
{
    R_Draw2DArray(points, verts, GL_LINE_STRIP);
}

void R_DrawLineLoop (int points, int* verts)
{
    R_Draw2DArray(points, verts, GL_LINE_LOOP);
}

void R_DrawLine (int* verts, float thickness)
{
    if (thickness > 0.0)
        glLineWidth(thickness);

    R_Draw2DArray(2, verts, GL_LINES);

    if (thickness > 0.0)
        glLineWidth(1.0);
}

void R_DrawPolygon (int points, int* verts)
{
    R_Draw2DArray(points, verts, GL_TRIANGLE_FAN);
}

typedef struct {
    int x;
    int y;
    int width;
    int height;
} rect_t;

#define MAX_CLIPRECT 16

static rect_t clipRect[MAX_CLIPRECT];

static int currentClipRect = 0;

static void R_RectIntersection (const rect_t* a, const rect_t* b, rect_t* out)
{
    out->x = (a->x > b->x) ? a->x : b->x;
    out->y = (a->y > b->y) ? a->y : b->y;
    out->width = ((a->x + a->width < b->x + b->width) ? a->x + a->width : b->x + b->width) - out->x;
    out->height = ((a->y + a->height < b->y + b->height) ? a->y + a->height : b->y + b->height) - out->y;
    if (out->width < 0)
        out->width = 0;
    if (out->height < 0)
        out->height = 0;
}

void R_PushClipRect (int x, int y, int width, int height)
{
    const int depth = currentClipRect;
    assert(depth < MAX_CLIPRECT);

    if (depth == 0) {
        clipRect[depth].x = x * viddef.rx;
        clipRect[depth].y = (viddef.virtualHeight - (y + height)) * viddef.ry;
        clipRect[depth].width = width * viddef.rx;
        clipRect[depth].height = height * viddef.ry;
    } else {
        rect_t rect;
        rect.x = x * viddef.rx;
        rect.y = (viddef.virtualHeight - (y + height)) * viddef.ry;
        rect.width = width * viddef.rx;
        rect.height = height * viddef.ry;
        R_RectIntersection(&clipRect[depth - 1], &rect, &clipRect[depth]);
    }

    glScissor(clipRect[depth].x, clipRect[depth].y, clipRect[depth].width, clipRect[depth].height);

    if (currentClipRect == 0)
        glEnable(GL_SCISSOR_TEST);
    currentClipRect++;
}

void R_PopClipRect (void)
{
    assert(currentClipRect > 0);
    currentClipRect--;
    if (currentClipRect == 0)
        glDisable(GL_SCISSOR_TEST);
    else {
        const int depth = currentClipRect - 1;
        glScissor(clipRect[depth].x, clipRect[depth].y, clipRect[depth].width, clipRect[depth].height);
    }
}

void R_CleanupDepthBuffer (int x, int y, int width, int height)
{
    const float nx = x * viddef.rx;
    const float ny = y * viddef.ry;
    const int nwidth = width * viddef.rx;
    const int nheight = height * viddef.ry;
    const GLboolean hasDepthTest = glIsEnabled(GL_DEPTH_TEST);
    const GLfloat bigZ = 2000.0f;
    const vec3_t points [] = { { nx, ny, bigZ }, { nx + nwidth, ny, bigZ }, { nx + nwidth, ny + nheight, bigZ }, { nx, ny + nheight, bigZ } };

    GLint depthFunc;
    glGetIntegerv(GL_DEPTH_FUNC, &depthFunc);

    /* we want to overwrite depth buffer not to have his constraints */
    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_ALWAYS);
    glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);

    R_BindArray(GL_VERTEX_ARRAY, GL_FLOAT, points);
    glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
    R_BindDefaultArray(GL_VERTEX_ARRAY);

    refdef.batchCount++;

    glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
    if (!hasDepthTest)
        glDisable(GL_DEPTH_TEST);
    glDepthFunc(depthFunc);
}

static void R_ComputeBoundingBox (const vec3_t mins, const vec3_t maxs, vec3_t bbox[8])
{
    /* compute a full bounding box */
    for (int i = 0; i < 8; i++) {
        bbox[i][0] = (i & 1) ? mins[0] : maxs[0];
        bbox[i][1] = (i & 2) ? mins[1] : maxs[1];
        bbox[i][2] = (i & 4) ? mins[2] : maxs[2];
    }
}

void R_DrawBoundingBoxes (void)
{
    const int step = 3 * 8;
    const int bboxes = r_bbox_array.bboxes_index / step;
    const GLushort indexes[] = { 2, 1, 0, 1, 4, 5, 1, 7, 3, 2, 7, 6, 2, 4, 0 };
    const GLushort indexes2[] = { 4, 6, 7 };

    if (!r_bbox_array.bboxes_index)
        return;

    glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);

    R_Color(nullptr);

    for (int i = 0; i < bboxes; i++) {
        const float* bbox = &r_bbox_array.bboxes[i * step];
        R_BindArray(GL_VERTEX_ARRAY, GL_FLOAT, bbox);
        /* Draw top and sides */
        glDrawElements(GL_TRIANGLE_FAN, 15, GL_UNSIGNED_SHORT, indexes);
        /* Draw bottom */
        glDrawElements(GL_TRIANGLE_FAN, 3, GL_UNSIGNED_SHORT, indexes2);
    }

    R_BindDefaultArray(GL_VERTEX_ARRAY);

    glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);

    r_bbox_array.bboxes_index = 0;
}

void R_DrawBoundingBoxBatched (const AABB& absbox)
{
    vec3_t bbox[8];
    const size_t max = lengthof(r_bbox_array.bboxes);

    if (r_bbox_array.bboxes_index >= max)
        return;

    R_ComputeBoundingBox(absbox.mins, absbox.maxs, bbox);

    for (int i = 0; i < 8; i++) {
        VectorCopy(bbox[i], &r_bbox_array.bboxes[r_bbox_array.bboxes_index]);
        r_bbox_array.bboxes_index += 3;
    }
}

void R_DrawBoundingBox (const AABB& absBox)
{
    vec3_t bbox[8];
    const GLushort indexes[] = { 2, 1, 0, 1, 4, 5, 1, 7, 3, 2, 7, 6, 2, 4, 0 };
    const GLushort indexes2[] = { 4, 6, 7 };

    R_ComputeBoundingBox(absBox.mins, absBox.maxs, bbox);

    glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);

    R_BindArray(GL_VERTEX_ARRAY, GL_FLOAT, bbox);
    /* Draw top and sides */
    glDrawElements(GL_TRIANGLE_STRIP, 15, GL_UNSIGNED_SHORT, indexes);
    /* Draw bottom */
    glDrawElements(GL_TRIANGLE_STRIP, 3, GL_UNSIGNED_SHORT, indexes2);
    R_BindDefaultArray(GL_VERTEX_ARRAY);

    glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
}

void R_DrawTexturedBox (const vec3_t a0, const vec3_t a1)
{
    const GLfloat texcoords[] = { 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, };
    const vec3_t bbox[] = {
                    { a0[0], a0[1], a0[2] }, { a0[0], a0[1], a1[2] }, { a1[0], a0[1], a1[2] }, { a1[0], a0[1], a0[2] },
                    { a1[0], a1[1], a0[2] }, { a1[0], a1[1], a1[2] }, { a0[0], a1[1], a1[2] }, { a0[0], a1[1], a0[2] },
                    { a0[0], a0[1], a0[2] }, { a0[0], a0[1], a1[2] }, { a1[0], a0[1], a1[2] }, { a1[0], a0[1], a0[2] },
                    { a1[0], a1[1], a0[2] }, { a1[0], a1[1], a1[2] }, { a0[0], a1[1], a1[2] }, { a0[0], a1[1], a0[2] } };
    const GLushort indexes[] = { 0, 1, 2, 1, 2, 3, 4, 5, 6, 6, 7, 4, 2 + 8, 3 + 8, 4 + 8, 2 + 8, 5 + 8, 4 + 8, 6 + 8, 7 + 8,
            0 + 8, 0 + 8, 1 + 8, 6 + 8, };

    R_BindArray(GL_TEXTURE_COORD_ARRAY, GL_FLOAT, texcoords);
    R_BindArray(GL_VERTEX_ARRAY, GL_FLOAT, bbox);

    /* Draw sides only */
    glDrawElements(GL_TRIANGLES, 8 * 3, GL_UNSIGNED_SHORT, indexes);

    R_BindDefaultArray(GL_VERTEX_ARRAY);
    R_BindDefaultArray(GL_TEXTURE_COORD_ARRAY);
}