DrawTexturePro and DrawRectanglePro optimizations

batch-drawing1.c

// Updated with bug fixes etc

// Draw a part of a texture (defined by a rectangle) with 'pro' parameters
// NOTE: origin is relative to destination rectangle size
void DrawTexturePro(Texture2D texture, Rectangle source, Rectangle dest, Vector2 origin, float rotation, Color tint)
{
    // Check if texture is valid
    if (texture.id > 0)
    {
        float width = (float)texture.width;
        float height = (float)texture.height;

        bool flipX = false;

        if (source.width < 0) { flipX = true; source.width *= -1; }
        if (source.height < 0) source.y -= source.height;

        Vector2 topLeft = { 0 };
        Vector2 topRight = { 0 };
        Vector2 bottomLeft = { 0 };
        Vector2 bottomRight = { 0 };

        // Only calculate rotation if needed
        if (rotation == 0.0f)
        {
            float x = dest.x - origin.x;
            float y = dest.y - origin.y;
            topLeft = (Vector2){ x, y };
            topRight = (Vector2){ x + dest.width, y };
            bottomLeft = (Vector2){ x, y + dest.height };
            bottomRight = (Vector2){ x + dest.width, y + dest.height };
        }
        else
        {
            float sinRotation = sinf(rotation*DEG2RAD);
            float cosRotation = cosf(rotation*DEG2RAD);
            float x = dest.x;
            float y = dest.y;
            float dx = -origin.x;
            float dy = -origin.y;

            topLeft.x = x + dx*cosRotation - dy*sinRotation;
            topLeft.y = y + dx*sinRotation + dy*cosRotation;

            topRight.x = x + (dx + dest.width)*cosRotation - dy*sinRotation;
            topRight.y = y + (dx + dest.width)*sinRotation + dy*cosRotation;

            bottomLeft.x = x + dx*cosRotation - (dy + dest.height)*sinRotation;
            bottomLeft.y = y + dx*sinRotation + (dy + dest.height)*cosRotation;

            bottomRight.x = x + (dx + dest.width)*cosRotation - (dy + dest.height)*sinRotation;
            bottomRight.y = y + (dx + dest.width)*sinRotation + (dy + dest.height)*cosRotation;
        }

        rlEnableTexture(texture.id);
        rlBegin(RL_QUADS);

            rlColor4ub(tint.r, tint.g, tint.b, tint.a);
            rlNormal3f(0.0f, 0.0f, 1.0f);                          // Normal vector pointing towards viewer

            // Top-left corner for texture and quad
            if (flipX) rlTexCoord2f((source.x + source.width)/width, source.y/height);
            else rlTexCoord2f(source.x/width, source.y/height);
            rlVertex2f(topLeft.x, topLeft.y);

            // Bottom-left corner for texture and quad
            if (flipX) rlTexCoord2f((source.x + source.width)/width, (source.y + source.height)/height);
            else rlTexCoord2f(source.x/width, (source.y + source.height)/height);
            rlVertex2f(bottomLeft.x, bottomLeft.y);

            // Bottom-right corner for texture and quad
            if (flipX) rlTexCoord2f(source.x/width, (source.y + source.height)/height);
            else rlTexCoord2f((source.x + source.width)/width, (source.y + source.height)/height);
            rlVertex2f(bottomRight.x, bottomRight.y);

            // Top-right corner for texture and quad
            if (flipX) rlTexCoord2f(source.x/width, source.y/height);
            else rlTexCoord2f((source.x + source.width)/width, source.y/height);
            rlVertex2f(topRight.x, topRight.y);

        rlEnd();
        rlDisableTexture();

        // NOTE: Vertex position can be transformed using matrices
        // but the process is way more costly than just calculating
        // the vertex positions manually, like done above.
        // I leave here the old implementation for educational pourposes,
        // just in case someone wants to do some performance test
        /*
        rlEnableTexture(texture.id);
        rlPushMatrix();
            rlTranslatef(dest.x, dest.y, 0.0f);
            if (rotation != 0.0f) rlRotatef(rotation, 0.0f, 0.0f, 1.0f);
            rlTranslatef(-origin.x, -origin.y, 0.0f);

            rlBegin(RL_QUADS);
                rlColor4ub(tint.r, tint.g, tint.b, tint.a);
                rlNormal3f(0.0f, 0.0f, 1.0f);                          // Normal vector pointing towards viewer

                // Bottom-left corner for texture and quad
                if (flipX) rlTexCoord2f((source.x + source.width)/width, source.y/height);
                else rlTexCoord2f(source.x/width, source.y/height);
                rlVertex2f(0.0f, 0.0f);

                // Bottom-right corner for texture and quad
                if (flipX) rlTexCoord2f((source.x + source.width)/width, (source.y + source.height)/height);
                else rlTexCoord2f(source.x/width, (source.y + source.height)/height);
                rlVertex2f(0.0f, dest.height);

                // Top-right corner for texture and quad
                if (flipX) rlTexCoord2f(source.x/width, (source.y + source.height)/height);
                else rlTexCoord2f((source.x + source.width)/width, (source.y + source.height)/height);
                rlVertex2f(dest.width, dest.height);

                // Top-left corner for texture and quad
                if (flipX) rlTexCoord2f(source.x/width, source.y/height);
                else rlTexCoord2f((source.x + source.width)/width, source.y/height);
                rlVertex2f(dest.width, 0.0f);
            rlEnd();
        rlPopMatrix();
        rlDisableTexture();
        */
    }
}

// Draw a color-filled rectangle with pro parameters
void DrawRectanglePro(Rectangle rec, Vector2 origin, float rotation, Color color)
{
    rlCheckRenderBatchLimit(4);

    Vector2 topLeft = { 0 };
    Vector2 topRight = { 0 };
    Vector2 bottomLeft = { 0 };
    Vector2 bottomRight = { 0 };

    // Only calculate rotation if needed
    if (rotation == 0.0f)
    {
        float x = rec.x - origin.x;
        float y = rec.y - origin.y;
        topLeft = (Vector2){ x, y };
        topRight = (Vector2){ x + rec.width, y };
        bottomLeft = (Vector2){ x, y + rec.height };
        bottomRight = (Vector2){ x + rec.width, y + rec.height };
    }
    else
    {
        float sinRotation = sinf(rotation*DEG2RAD);
        float cosRotation = cosf(rotation*DEG2RAD);
        float x = rec.x;
        float y = rec.y;
        float dx = -origin.x;
        float dy = -origin.y;

        topLeft.x = x + dx*cosRotation - dy*sinRotation;
        topLeft.y = y + dx*sinRotation + dy*cosRotation;

        topRight.x = x + (dx + rec.width)*cosRotation - dy*sinRotation;
        topRight.y = y + (dx + rec.width)*sinRotation + dy*cosRotation;

        bottomLeft.x = x + dx*cosRotation - (dy + rec.height)*sinRotation;
        bottomLeft.y = y + dx*sinRotation + (dy + rec.height)*cosRotation;

        bottomRight.x = x + (dx + rec.width)*cosRotation - (dy + rec.height)*sinRotation;
        bottomRight.y = y + (dx + rec.width)*sinRotation + (dy + rec.height)*cosRotation;
    }

    rlEnableTexture(rlGetShapesTexture().id);
    rlBegin(RL_QUADS);

        rlNormal3f(0.0f, 0.0f, 1.0f);
        rlColor4ub(color.r, color.g, color.b, color.a);

        rlTexCoord2f(rlGetShapesTextureRec().x/rlGetShapesTexture().width, rlGetShapesTextureRec().y/rlGetShapesTexture().height);
        rlVertex2f(topLeft.x, topLeft.y);

        rlTexCoord2f(rlGetShapesTextureRec().x/rlGetShapesTexture().width, (rlGetShapesTextureRec().y + rlGetShapesTextureRec().height)/rlGetShapesTexture().height);
        rlVertex2f(bottomLeft.x, bottomLeft.y);

        rlTexCoord2f((rlGetShapesTextureRec().x + rlGetShapesTextureRec().width)/rlGetShapesTexture().width, (rlGetShapesTextureRec().y + rlGetShapesTextureRec().height)/rlGetShapesTexture().height);
        rlVertex2f(bottomRight.x, bottomRight.y);

        rlTexCoord2f((rlGetShapesTextureRec().x + rlGetShapesTextureRec().width)/rlGetShapesTexture().width, rlGetShapesTextureRec().y/rlGetShapesTexture().height);
        rlVertex2f(topRight.x, topRight.y);

    rlEnd();
    rlDisableTexture();
}

Amazing!

Update. The previous numbers were using the default debug build.

Testing with a optimized release build can reach around 150k bunnies.

The original matrix version reaches around 80k. If I change it so it only applies rotation if rotation != 0.0f then it can reach 130k.