mirror of
https://github.com/curioustorvald/Terrarum.git
synced 2026-03-07 20:31:51 +09:00
100 lines
3.5 KiB
GLSL
100 lines
3.5 KiB
GLSL
#version 120
|
|
#ifdef GL_ES
|
|
precision mediump float;
|
|
#endif
|
|
#extension GL_EXT_gpu_shader4 : enable
|
|
|
|
//layout(origin_upper_left) in vec4 gl_FragCoord; // commented; requires #version 150 or later
|
|
// gl_FragCoord is origin to bottom-left
|
|
|
|
varying vec4 v_color;
|
|
varying vec2 v_texCoords;
|
|
uniform sampler2D u_texture;
|
|
|
|
|
|
uniform vec2 screenDimension;
|
|
uniform vec2 tilesInAxes; // vec2(tiles_in_horizontal, tiles_in_vertical)
|
|
|
|
uniform ivec2 tilemapDimension;
|
|
uniform sampler2D tilemap; // RGB888, A is optional and will be completely ignored
|
|
|
|
uniform sampler2D tilesAtlas;
|
|
uniform sampler2D backgroundTexture;
|
|
|
|
uniform ivec2 tilesInAtlas = ivec2(256, 256);
|
|
uniform ivec2 atlasTexSize = ivec2(4096, 4096);
|
|
ivec2 tileSizeInPx = atlasTexSize / tilesInAtlas;
|
|
|
|
uniform vec4 colourFilter = vec4(1, 1, 1, 1); // used by WALL to darken it
|
|
|
|
uniform ivec2 cameraTranslation = ivec2(0, 0);
|
|
|
|
|
|
ivec2 getTileXY(int tileNumber) {
|
|
return ivec2(tileNumber % int(tilesInAtlas.x), tileNumber / int(tilesInAtlas.x));
|
|
}
|
|
|
|
// return: int=0xrrggbb
|
|
int _colToInt(vec4 color) {
|
|
return int(color.b * 255) | (int(color.g * 255) << 8) | (int(color.r * 255) << 16);
|
|
}
|
|
|
|
// 0x0rggbb where int=0xaarrggbb
|
|
// return: [0..1048575]
|
|
int getTileFromColor(vec4 color) {
|
|
return _colToInt(color) & 0x0FFFFF;
|
|
}
|
|
|
|
// 0xr00000 where int=0xaarrggbb
|
|
// return: [0..15]
|
|
int getBreakageFromColor(vec4 color) {
|
|
return (_colToInt(color) >> 20) & 0xF;
|
|
}
|
|
|
|
void main() {
|
|
|
|
// READ THE FUCKING MANUAL, YOU DONKEY !! //
|
|
// This code purposedly uses flipped fragcoord. //
|
|
// Make sure you don't use gl_FragCoord unknowingly! //
|
|
|
|
|
|
// default gl_FragCoord takes half-integer (represeting centre of the pixel) -- could be useful for phys solver?
|
|
// This one, however, takes exact integer by rounding down. //
|
|
vec2 overscannedScreenDimension = tilesInAxes * tileSizeInPx; // one used by the tileFromMap
|
|
vec2 flippedFragCoord = vec2(gl_FragCoord.x, screenDimension.y - gl_FragCoord.y) + cameraTranslation; // NO IVEC2!!; this flips Y
|
|
|
|
vec2 pxCoord = flippedFragCoord.xy;
|
|
|
|
// TODO do I really need mediump for this thing ? (default to smapler2D is lowp)
|
|
vec4 tileFromMap = texture2D(tilemap, flippedFragCoord / overscannedScreenDimension); // <- THE CULPRIT
|
|
int tile = getTileFromColor(tileFromMap);
|
|
int breakage = getBreakageFromColor(tileFromMap);
|
|
|
|
|
|
ivec2 tileXY = getTileXY(tile);
|
|
ivec2 breakageXY = getTileXY(breakage + 5); // +5 is hard-coded constant that depends on the atlas
|
|
|
|
|
|
mediump vec2 coordInTile = mod(pxCoord, tileSizeInPx) / tileSizeInPx; // 0..1 regardless of tile position in atlas
|
|
|
|
// don't really need highp here; read the GLES spec
|
|
mediump vec2 singleTileSizeInUV = vec2(1) / tilesInAtlas; // constant 0.00390625 for unmodified default uniforms
|
|
|
|
mediump vec2 uvCoordForTile = coordInTile * singleTileSizeInUV; // 0..0.00390625 regardless of tile position in atlas
|
|
|
|
mediump vec2 uvCoordOffsetTile = tileXY * singleTileSizeInUV; // where the tile starts in the atlas, using uv coord (0..1)
|
|
mediump vec2 uvCoordOffsetBreakage = breakageXY * singleTileSizeInUV;
|
|
|
|
mediump vec2 finalUVCoordForTile = uvCoordForTile + uvCoordOffsetTile;// where we should be actually looking for in atlas, using UV coord (0..1)
|
|
mediump vec2 finalUVCoordForBreakage = uvCoordForTile + uvCoordOffsetBreakage;
|
|
|
|
|
|
// blending a breakage tex with main tex
|
|
|
|
vec4 finalTile = texture2D(tilesAtlas, finalUVCoordForTile);
|
|
vec4 finalBreakage = texture2D(tilesAtlas, finalUVCoordForBreakage);
|
|
|
|
gl_FragColor = colourFilter * (mix(finalTile, finalBreakage, finalBreakage.a));
|
|
|
|
}
|