From 046b2b7a38ec66208c96be59c030294b6d10351b Mon Sep 17 00:00:00 2001
From: dec05eba <dec05eba@protonmail.com>
Date: Sat, 16 Oct 2021 19:36:53 +0200
Subject: Add font rendering

---
 src/graphics/texture.c | 54 +++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 49 insertions(+), 5 deletions(-)

(limited to 'src/graphics/texture.c')

diff --git a/src/graphics/texture.c b/src/graphics/texture.c
index b3a1fab..383f3f8 100644
--- a/src/graphics/texture.c
+++ b/src/graphics/texture.c
@@ -9,32 +9,51 @@
 #define STB_IMAGE_IMPLEMENTATION
 #include "../../external/stb_image.h"
 
+/* TODO: Check for glTexImage2D failure */
+
 static int mgl_texture_format_to_opengl_format(mgl_texture_format format) {
     switch(format) {
+        case MGL_TEXTURE_ALPHA:      return GL_ALPHA8;
         case MGL_TEXTURE_GRAY:       return GL_LUMINANCE8;
         case MGL_TEXTURE_GRAY_ALPHA: return GL_LUMINANCE8_ALPHA8;
         case MGL_TEXTURE_RGB:        return GL_RGB8;
-        case MGL_TEXTURE_RGB_ALPHA:  return GL_RGBA8;
+        case MGL_TEXTURE_RGBA:       return GL_RGBA8;
     }
     return 0;
 }
 
 static int mgl_texture_format_to_compressed_opengl_format(mgl_texture_format format) {
     switch(format) {
+        case MGL_TEXTURE_ALPHA:      return GL_ALPHA8;
         case MGL_TEXTURE_GRAY:       return GL_LUMINANCE8;
         case MGL_TEXTURE_GRAY_ALPHA: return GL_LUMINANCE8_ALPHA8;
         case MGL_TEXTURE_RGB:        return GL_COMPRESSED_RGB_S3TC_DXT1_EXT;
-        case MGL_TEXTURE_RGB_ALPHA:  return GL_COMPRESSED_RGBA_S3TC_DXT5_EXT;
+        case MGL_TEXTURE_RGBA:       return GL_COMPRESSED_RGBA_S3TC_DXT5_EXT;
     }
     return 0;
 }
 
 static int mgl_texture_format_to_source_opengl_format(mgl_texture_format format) {
     switch(format) {
-        case MGL_TEXTURE_GRAY:       return GL_LUMINANCE8_ALPHA8;
+        case MGL_TEXTURE_ALPHA:      return GL_ALPHA;
+        case MGL_TEXTURE_GRAY:       return GL_LUMINANCE8;
         case MGL_TEXTURE_GRAY_ALPHA: return GL_LUMINANCE8_ALPHA8;
         case MGL_TEXTURE_RGB:        return GL_RGB;
-        case MGL_TEXTURE_RGB_ALPHA:  return GL_RGBA;
+        case MGL_TEXTURE_RGBA:       return GL_RGBA;
+    }
+    return 0;
+}
+
+static mgl_texture_format stbi_format_to_mgl_texture_format(int stbi_format) {
+    switch(stbi_format) {
+        case STBI_grey:
+            return MGL_TEXTURE_GRAY;
+        case STBI_grey_alpha:
+            return MGL_TEXTURE_GRAY_ALPHA;
+        case STBI_rgb:
+            return MGL_TEXTURE_RGB;
+        case STBI_rgb_alpha:
+            return MGL_TEXTURE_RGBA;
     }
     return 0;
 }
@@ -50,11 +69,12 @@ int mgl_texture_load_from_file(mgl_texture *self, const char *filepath, mgl_text
         fprintf(stderr, "Error: failed to load image %s, error: %s\n", filepath, stbi_failure_reason());
         return -1;
     }
-    self->format = format;
+    self->format = stbi_format_to_mgl_texture_format(format);
 
     mgl_context *context = mgl_get_context();
     context->gl.glGenTextures(1, &self->id);
     if(self->id == 0) {
+        fprintf(stderr, "Error: failed to load image %s", filepath);
         stbi_image_free(image_data);
         return -1;
     }
@@ -73,6 +93,30 @@ int mgl_texture_load_from_file(mgl_texture *self, const char *filepath, mgl_text
     return 0;
 }
 
+int mgl_texture_load_from_memory(mgl_texture *self, const unsigned char *data, int width, int height, mgl_texture_format format, mgl_texture_load_options *load_options) {
+    self->id = 0;
+    self->width = width;
+    self->height = height;
+    self->format = format;
+
+    mgl_context *context = mgl_get_context();
+    context->gl.glGenTextures(1, &self->id);
+    if(self->id == 0)
+        return -1;
+
+    const int opengl_texture_format = load_options && load_options->compressed ? mgl_texture_format_to_compressed_opengl_format(self->format) : mgl_texture_format_to_opengl_format(self->format);
+
+    context->gl.glBindTexture(GL_TEXTURE_2D, self->id);
+    context->gl.glTexImage2D(GL_TEXTURE_2D, 0, opengl_texture_format, self->width, self->height, 0, mgl_texture_format_to_source_opengl_format(self->format), GL_UNSIGNED_BYTE, data);
+    context->gl.glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+    context->gl.glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+    context->gl.glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    context->gl.glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    context->gl.glBindTexture(GL_TEXTURE_2D, 0);
+
+    return 0;
+}
+
 void mgl_texture_unload(mgl_texture *self) {
     mgl_context *context = mgl_get_context();
     if(self->id) {
-- 
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