mirror of
https://github.com/curioustorvald/Terrarum.git
synced 2026-03-07 20:31:51 +09:00
107 lines
4.2 KiB
GLSL
107 lines
4.2 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; // size of the tilemap texture; vec2(tiles_in_horizontal, tiles_in_vertical)
|
|
|
|
uniform sampler2D tilemap; // RGBA8888
|
|
|
|
uniform sampler2D tilesAtlas; // terrain, wire, fluids, etc.
|
|
uniform sampler2D tilesBlendAtlas; // alternative terrain for the weather mix (e.g. yellowed grass)
|
|
uniform float tilesBlend = 0.0; // percentage of blending [0f..1f]. 0: draws tilesAtlas, 1: draws tilesBlendAtlas
|
|
|
|
uniform vec2 tilesInAtlas = ivec2(256.0, 256.0);
|
|
uniform vec2 atlasTexSize = ivec2(4096.0, 4096.0);
|
|
vec2 tileSizeInPx = atlasTexSize / tilesInAtlas; // should be like ivec2(16.0, 16.0)
|
|
|
|
uniform vec4 colourFilter = vec4(1, 1, 1, 1); // used by WALL to darken it
|
|
|
|
uniform ivec2 cameraTranslation = ivec2(0, 0); // used to offset the drawing; it's integer because we want the drawing to be pixel-aligned
|
|
|
|
uniform float drawBreakage = 1.0; // set it to 0f to not draw breakage, 1f to draw it; NEVER set to any other values.
|
|
|
|
|
|
ivec2 getTileXY(int tileNumber) {
|
|
return ivec2(tileNumber % int(tilesInAtlas.x), tileNumber / int(tilesInAtlas.x));
|
|
}
|
|
|
|
// return: int=0xaarrggbb
|
|
int _colToInt(vec4 color) {
|
|
return int(color.b * 255) | (int(color.g * 255) << 8) | (int(color.r * 255) << 16) | (int(color.a * 255) << 24);
|
|
}
|
|
|
|
// 0x0rggbb where int=0xaarrggbb
|
|
// return: [0..1048575]
|
|
int getTileFromColor(vec4 color) {
|
|
return _colToInt(color) & 0xFFFFF;
|
|
}
|
|
|
|
// 0x00r00000 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! //
|
|
// Remember, if there's a compile error, shader SILENTLY won't do anything //
|
|
|
|
|
|
// 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; // how many tiles will fit into a screen; one used by the tileFromMap; we need this because screen size is not integer multiple of the tile size
|
|
vec2 flippedFragCoord = vec2(gl_FragCoord.x, screenDimension.y - gl_FragCoord.y) + cameraTranslation; // NO IVEC2!!; this flips Y
|
|
|
|
// get required tile numbers //
|
|
|
|
vec4 tileFromMap = texture2D(tilemap, flippedFragCoord / overscannedScreenDimension); // raw tile number
|
|
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
|
|
|
|
// calculate the UV coord value for texture sampling //
|
|
|
|
// don't really need highp here; read the GLES spec
|
|
vec2 uvCoordForTile = (mod(flippedFragCoord, tileSizeInPx) / tileSizeInPx) / tilesInAtlas; // 0..0.00390625 regardless of tile position in atlas
|
|
vec2 uvCoordOffsetTile = tileXY / tilesInAtlas; // where the tile starts in the atlas, using uv coord (0..1)
|
|
vec2 uvCoordOffsetBreakage = breakageXY / tilesInAtlas;
|
|
|
|
// get final UV coord for the actual sampling //
|
|
|
|
vec2 finalUVCoordForTile = uvCoordForTile + uvCoordOffsetTile;// where we should be actually looking for in atlas, using UV coord (0..1)
|
|
vec2 finalUVCoordForBreakage = uvCoordForTile + uvCoordOffsetBreakage;
|
|
|
|
// blending a breakage tex with main tex //
|
|
|
|
vec4 tileCol = texture2D(tilesAtlas, finalUVCoordForTile);
|
|
vec4 tileAltCol = texture2D(tilesBlendAtlas, finalUVCoordForTile);
|
|
|
|
vec4 finalTile = mix(tileCol, tileAltCol, tilesBlend);
|
|
|
|
vec4 finalBreakage = drawBreakage * texture2D(tilesAtlas, finalUVCoordForBreakage); // drawBreakeage = 0 to not draw, = 1 to draw
|
|
|
|
vec4 finalColor = vec4(mix(finalTile.rgb, finalBreakage.rgb, finalBreakage.a), finalTile.a);
|
|
|
|
gl_FragColor = colourFilter * finalColor;
|
|
|
|
}
|