Correctly align text rendering to baseline

src/AssetManager.c

@@ -9,6 +9,12 @@
 #include "Dengine/Platform.h"
 #include "Dengine/AssetManager.h"
 
+//#define WT_RENDER_FONT_FILE
+#ifdef WT_RENDER_FONT_FILE
+#define STB_IMAGE_WRITE_IMPLEMENTATION
+#include <STB/stb_image_write.h>
+#endif
+
 Texture *asset_getTexture(AssetManager *assetManager, const enum TexList type)
 {
 	if (type < texlist_count)
@@ -251,6 +257,9 @@ const i32 asset_loadTTFont(AssetManager *assetManager, const char *filePath)
 	i32 glyphsRemaining = numGlyphs;
 	i32 glyphsOnCurrRow = glyphsPerRow;
 
+	// TODO(doyle): We copy over the bitmap direct to the font sheet, should we
+	// align the baselines up so we don't need to do baseline adjusting at
+	// render?
 	i32 atlasIndex = 0;
 	for (i32 row = 0; row < MAX_TEXTURE_SIZE; row++)
 	{
@@ -331,6 +340,12 @@ const i32 asset_loadTTFont(AssetManager *assetManager, const char *filePath)
 	                         CAST(u8 *)fontBitmap);
 	assetManager->textures[texlist_font] = tex;
 
+#ifdef WT_RENDER_FONT_FILE
+	/* save out a 4 channel image */
+	stbi_write_png("out.png", MAX_TEXTURE_SIZE, MAX_TEXTURE_SIZE, 4, fontBitmap,
+	               MAX_TEXTURE_SIZE * 4);
+#endif
+
 	font->tex = &assetManager->textures[texlist_font];
 	font->atlas = &assetManager->texAtlas[texlist_font];
 

src/Renderer.c

@@ -1,6 +1,8 @@
 #include "Dengine/OpenGL.h"
 #include "Dengine/Renderer.h"
 
+#define RENDER_BOUNDING_BOX FALSE
+
 void renderer_entity(Renderer *renderer, Entity *entity, f32 rotate, v3 color)
 {
 	renderer_object(renderer, entity->pos, entity->size, rotate, color,
@@ -28,7 +30,7 @@ void renderer_object(Renderer *renderer, v2 pos, v2 size, f32 rotate, v3 color,
 	// TODO(doyle): Unimplemented
 	// this->shader->uniformSetVec3f("spriteColor", color);
 
-#if 1
+#if RENDER_BOUNDING_BOX
 	glBindVertexArray(renderer->vao);
 	glDrawArrays(GL_TRIANGLE_STRIP, 0, renderer->numVertexesInVbo);
 	glBindVertexArray(0);

src/WorldTraveller.c

@@ -318,7 +318,6 @@ void worldTraveller_gameUpdateAndRender(GameState *state, const f32 dt)
 	RenderQuad worldQuads[ARRAY_COUNT(world->tiles)] = {0};
 	i32 quadIndex = 0;
 
-
 	/* Render background tiles */
 	const v2 tileSize = V2(CAST(f32) state->tileSize, CAST(f32) state->tileSize);
 	for (i32 i = 0; i < ARRAY_COUNT(world->tiles); i++)
@@ -358,16 +357,7 @@ void worldTraveller_gameUpdateAndRender(GameState *state, const f32 dt)
 		i32 codepoint = string[i];
 		i32 relativeIndex = codepoint - font->codepointRange.x;
 		CharMetrics charMetric = font->charMetrics[relativeIndex];
-
-		i32 charBaseline = (font->maxSize.h - charMetric.trueSize.h);
-		if (codepoint == 'a')
-		{
-			yPosOnScreen = baseline - charBaseline;
-		}
-		else
-		{
-			yPosOnScreen = baseline;
-		}
+		yPosOnScreen = baseline - charMetric.offset.y;
 
 		const v4 charRectOnScreen = getRect(
 		    V2(xPosOnScreen, yPosOnScreen),

src/include/Dengine/AssetManager.h

@@ -32,6 +32,7 @@ typedef struct TexAtlas
 	v4 texRect[128];
 } TexAtlas;
 
+// TODO(doyle): We only use the offset and advance metric at the moment, remove?
 typedef struct FontMetrics
 {
 	i32 ascent;
@@ -43,6 +44,7 @@ typedef struct CharMetrics
 {
 	i32 advance;
 	i32 leftSideBearing;
+	// TODO(doyle): Utilise kerning
 	i32 *kerning;
 	v2i offset;
 	v2i trueSize;